diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index aa834d64..58700991 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,32 +1,98 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2017-01-03 04:53:24 +0100 using RuboCop version 0.45.0.
+# on 2018-02-11 20:53:46 +0000 using RuboCop version 0.52.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
-# Offense count: 3
+# Offense count: 1
+Lint/BooleanSymbol:
+  Exclude:
+    - 'app/controllers/setup_controller.rb'
+
+# Offense count: 10
 Metrics/AbcSize:
   Max: 32
 
-# Offense count: 3
-# Configuration parameters: CountComments.
+# Offense count: 26
+# Configuration parameters: CountComments, ExcludedMethods.
 Metrics/BlockLength:
   Max: 121
 
-# Offense count: 156
-# Configuration parameters: AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives.
-# URISchemes: http, https
-Metrics/LineLength:
-  Max: 120
-
-# Offense count: 7
+# Offense count: 12
 # Configuration parameters: CountComments.
 Metrics/MethodLength:
   Max: 17
 
-# Offense count: 24
+# Offense count: 2
+# Configuration parameters: Include.
+# Include: db/migrate/*.rb
+Rails/CreateTableWithTimestamps:
+  Exclude:
+    - 'db/migrate/20170103063306_create_author_submission_join_table.rb'
+    - 'db/migrate/20170108014805_create_memberships_teams_join_table.rb'
+
+# Offense count: 6
+Rails/FilePath:
+  Exclude:
+    - 'app/controllers/setup_controller.rb'
+    - 'config/environments/development.rb'
+    - 'config/initializers/paperclip.rb'
+    - 'config/initializers/sidekiq.rb'
+    - 'lib/tasks/cucumber.rake'
+
+# Offense count: 3
+# Configuration parameters: Include.
+# Include: app/models/**/*.rb
+Rails/HasManyOrHasOneDependent:
+  Exclude:
+    - 'app/models/membership.rb'
+    - 'app/models/team.rb'
+    - 'app/models/test.rb'
+
+# Offense count: 4
+# Configuration parameters: Include.
+# Include: app/models/**/*.rb
+Rails/InverseOf:
+  Exclude:
+    - 'app/models/course.rb'
+    - 'app/models/submission.rb'
+    - 'app/models/team.rb'
+    - 'app/models/user.rb'
+
+# Offense count: 1
+# Configuration parameters: Include.
+# Include: db/migrate/*.rb
+Rails/ReversibleMigration:
+  Exclude:
+    - 'db/migrate/20170108202754_drop_author_submissions_join_table.rb'
+
+# Offense count: 2
+# Configuration parameters: Blacklist.
+# Blacklist: decrement!, decrement_counter, increment!, increment_counter, toggle!, touch, update_all, update_attribute, update_column, update_columns, update_counters
+Rails/SkipsModelValidations:
+  Exclude:
+    - 'app/controllers/omniauth_callbacks_controller.rb'
+
+# Offense count: 83
 Style/Documentation:
   Enabled: false
 
+# Offense count: 1
+# Configuration parameters: .
+# SupportedStyles: annotated, template, unannotated
+Style/FormatStringToken:
+  EnforcedStyle: unannotated
+
+# Offense count: 2
+Style/MixinUsage:
+  Exclude:
+    - 'bin/setup'
+    - 'bin/update'
+
+# Offense count: 260
+# Configuration parameters: AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
+# URISchemes: http, https
+Metrics/LineLength:
+  Max: 130
diff --git a/Capfile b/Capfile
index 343d60b9..42b57d94 100644
--- a/Capfile
+++ b/Capfile
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Load DSL and Setup Up Stages
 require 'capistrano/setup'
 
diff --git a/Gemfile b/Gemfile
index 161174fb..9a310f43 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 source 'https://rubygems.org'
 
 git_source(:github) do |repo_name|
@@ -25,8 +26,8 @@ gem 'coffee-rails', '~> 4.2'
 #
 gem 'haml'
 
-gem 'paperclip', '~> 5.0'
 gem 'aws-sdk', '~> 2.3.0'
+gem 'paperclip', '~> 5.0'
 gem 'rubyzip'
 
 # Use jquery as the JavaScript library
@@ -60,34 +61,34 @@ gem 'git_stats'
 gem 'sidekiq'
 
 group :development, :test do
-  gem 'pry'
   gem 'factory_girl_rails'
   gem 'faker'
+  gem 'pry'
 end
 
 group :development do
   # Access an IRB console on exception pages or by using <%= console %> anywhere in the code.
-  gem 'web-console', '>= 3.3.0'
   gem 'listen', '~> 3.0.5'
+  gem 'web-console', '>= 3.3.0'
   # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
   gem 'spring'
   gem 'spring-watcher-listen', '~> 2.0.0'
 
-  gem 'letter_opener'
   gem 'happy_seed'
+  gem 'letter_opener'
 
-  gem 'rubocop', require: false
   gem 'brakeman', require: false
+  gem 'rubocop', require: false
 
   # capistrano
 
   gem 'capistrano', '~> 3.8', require: false, group: :development
   # Deploy with capistrano, see config/deploy.rb
-  gem 'capistrano-rails', '~> 1.1', require: false
   gem 'capistrano-bundler', '~> 1.1', require: false
+  gem 'capistrano-postgresql', '~> 4.2.1', require: false
+  gem 'capistrano-rails', '~> 1.1', require: false
   gem 'capistrano-safe-deploy-to', '~> 1.1.1', require: false
   gem 'rvm1-capistrano3', '~> 1.3.2', require: false
-  gem 'capistrano-postgresql', '~> 4.2.1', require: false
   # gem 'capistrano-memcached', '~> 1.2.0', require: false
   gem 'capistrano-unicorn-nginx', '~> 4.1', require: false
   # gem 'capistrano-faster-assets', '~> 1.0.2', require: false
@@ -95,49 +96,49 @@ group :development do
 end
 
 group :test do
-  gem 'rspec-rails'
+  gem 'capybara'
+  gem 'rails-controller-testing'
+  gem 'rspec-collection_matchers'
   gem 'rspec-mocks'
+  gem 'rspec-rails'
   gem 'spring-commands-rspec'
-  gem 'rspec-collection_matchers'
   gem 'vcr'
   gem 'webmock'
-  gem 'rails-controller-testing'
-  gem 'capybara'
 end
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
-gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
+gem 'tzinfo-data', platforms: %i[mingw mswin x64_mingw jruby]
 
+gem 'bh'
 gem 'bootstrap-sass'
-gem 'modernizr-rails'
+gem 'cancancan'
+gem 'devise', '~> 4.2'
+gem 'github_webhook', '~> 1.0.2'
 gem 'meta-tags', require: 'meta_tags'
-gem 'responders', '~> 2.0'
-gem 'bh'
-gem 'premailer-rails'
+gem 'modernizr-rails'
 gem 'nokogiri'
-gem 'devise', '~> 4.2'
-gem 'cancancan'
+gem 'octokit'
 gem 'omniauth'
-gem 'omniauth-oauth2', '1.3.1'
 gem 'omniauth-facebook'
 gem 'omniauth-github'
-gem 'octokit'
-gem 'github_webhook', '~> 1.0.2'
+gem 'omniauth-oauth2', '1.3.1'
+gem 'premailer-rails'
+gem 'responders', '~> 2.0'
 
 gem 'omniauth-google-oauth2'
 # gem 'google-api-client', require: 'google/api_client'
 
-gem 'omniauth-twitter'
-gem 'twitter'
-gem 'ckeditor'
 gem 'activeadmin', github: 'activeadmin'
-gem 'inherited_resources', github: 'activeadmin/inherited_resources'
-gem 'ransack', github: 'activerecord-hackery/ransack'
-gem 'kaminari', github: 'amatsuda/kaminari', branch: '0-17-stable'
-gem 'formtastic', github: 'justinfrench/formtastic'
-gem 'draper', github: 'audionerd/draper', branch: 'rails5', ref: 'e816e0e587'
 gem 'activemodel-serializers-xml', github: 'rails/activemodel-serializers-xml'
+gem 'ckeditor'
 gem 'dateslices'
+gem 'draper', github: 'audionerd/draper', branch: 'rails5', ref: 'e816e0e587'
+gem 'formtastic', github: 'justinfrench/formtastic'
 gem 'gretel'
+gem 'inherited_resources', github: 'activeadmin/inherited_resources'
+gem 'kaminari', github: 'amatsuda/kaminari', branch: '0-17-stable'
+gem 'omniauth-twitter'
+gem 'ransack', github: 'activerecord-hackery/ransack'
+gem 'twitter'
 
 ruby '~> 2.4'
diff --git a/Gemfile.lock b/Gemfile.lock
index 87eee252..798c0ec3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -134,7 +134,7 @@ GEM
     arbre (1.1.1)
       activesupport (>= 3.0.0)
     arel (7.1.4)
-    ast (2.3.0)
+    ast (2.4.0)
     autoprefixer-rails (6.6.0)
       execjs
     aws-sdk (2.3.22)
@@ -362,8 +362,9 @@ GEM
       cocaine (~> 0.5.5)
       mime-types
       mimemagic (~> 0.3.0)
-    parser (2.3.1.4)
-      ast (~> 2.2)
+    parallel (1.12.1)
+    parser (2.4.0.2)
+      ast (~> 2.3)
     pg (0.18.2)
     polyamorous (1.3.1)
       activerecord (>= 3.0)
@@ -411,7 +412,7 @@ GEM
       method_source
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
-    rainbow (2.1.0)
+    rainbow (3.0.0)
     raindrops (0.19.0)
     rake (12.0.0)
     rb-fsevent (0.9.8)
@@ -443,13 +444,14 @@ GEM
       rspec-mocks (~> 3.5.0)
       rspec-support (~> 3.5.0)
     rspec-support (3.5.0)
-    rubocop (0.45.0)
-      parser (>= 2.3.1.1, < 3.0)
+    rubocop (0.52.1)
+      parallel (~> 1.10)
+      parser (>= 2.4.0.2, < 3.0)
       powerpack (~> 0.1)
-      rainbow (>= 1.99.1, < 3.0)
+      rainbow (>= 2.2.2, < 4.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (~> 1.0, >= 1.0.1)
-    ruby-progressbar (1.8.1)
+    ruby-progressbar (1.9.0)
     rubyzip (1.1.7)
     rvm1-capistrano3 (1.3.2.2)
       capistrano (~> 3.0)
@@ -512,7 +514,7 @@ GEM
     unf (0.1.4)
       unf_ext
     unf_ext (0.0.7.2)
-    unicode-display_width (1.1.1)
+    unicode-display_width (1.3.0)
     unicorn (5.3.0)
       kgio (~> 2.6)
       raindrops (~> 0.7)
diff --git a/Guardfile b/Guardfile
index 8a788cf3..bd8203e6 100644
--- a/Guardfile
+++ b/Guardfile
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # A sample Guardfile
 # More info at https://github.com/guard/guard#readme
 
@@ -67,7 +68,7 @@ guard :rspec, cmd: 'bin/rspec', all_on_start: true do
   dsl.watch_spec_files_for(ruby.lib_files)
 
   # Rails files
-  rails = dsl.rails(view_extensions: %w(erb haml slim))
+  rails = dsl.rails(view_extensions: %w[erb haml slim])
   dsl.watch_spec_files_for(rails.app_files)
   dsl.watch_spec_files_for(rails.views)
 
diff --git a/Rakefile b/Rakefile
index 84f2bc39..488c551f 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Add your own tasks in files placed in lib/tasks ending in .rake,
 # for example lib/tasks/capistrano.rake, and they will automatically be available to Rake.
 
diff --git a/app/admin/dashboard.rb b/app/admin/dashboard.rb
index 0e7ae04d..89a797ca 100644
--- a/app/admin/dashboard.rb
+++ b/app/admin/dashboard.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 ActiveAdmin.register_page 'Dashboard' do
   menu priority: 1, label: proc { I18n.t('active_admin.dashboard') }
 
diff --git a/app/admin/user.rb b/app/admin/user.rb
index 740692c6..790b29d9 100644
--- a/app/admin/user.rb
+++ b/app/admin/user.rb
@@ -1,2 +1,3 @@
 # frozen_string_literal: true
+
 ActiveAdmin.register User
diff --git a/app/channels/application_cable/channel.rb b/app/channels/application_cable/channel.rb
index 51e3e936..9aec2305 100644
--- a/app/channels/application_cable/channel.rb
+++ b/app/channels/application_cable/channel.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 module ApplicationCable
   class Channel < ActionCable::Channel::Base
   end
diff --git a/app/channels/application_cable/connection.rb b/app/channels/application_cable/connection.rb
index 3a9a78bf..d8671d5c 100644
--- a/app/channels/application_cable/connection.rb
+++ b/app/channels/application_cable/connection.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 module ApplicationCable
   class Connection < ActionCable::Connection::Base
     identified_by :current_user
diff --git a/app/channels/submissions_channel.rb b/app/channels/submissions_channel.rb
index 3cf1e898..79c68ae6 100644
--- a/app/channels/submissions_channel.rb
+++ b/app/channels/submissions_channel.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class SubmissionsChannel < ApplicationCable::Channel
   def subscribed
     stream_from "submissions_#{current_user.id}"
diff --git a/app/controllers/admin/stats_controller.rb b/app/controllers/admin/stats_controller.rb
index c66d4c51..482b5dba 100644
--- a/app/controllers/admin/stats_controller.rb
+++ b/app/controllers/admin/stats_controller.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 module Admin
   class StatsController < ApplicationController
     before_action :authenticate_admin_user!
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index c916351a..87f7c9e1 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class ApplicationController < ActionController::Base
   check_authorization unless: :devise_controller?
 
@@ -12,8 +13,7 @@ def redirect_to_primary_domain
     redirect_to "#{request.protocol}#{ENV.fetch('DOMAIN_NAME')}#{request.fullpath}", status: :moved_permanently
   end
 
-  def page_title
-  end
+  def page_title; end
 
   def access_denied(exception)
     redirect_to root_path, alert: exception.message
diff --git a/app/controllers/assignments_controller.rb b/app/controllers/assignments_controller.rb
index b21a8614..103cfaf4 100644
--- a/app/controllers/assignments_controller.rb
+++ b/app/controllers/assignments_controller.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AssignmentsController < ApplicationController
   load_and_authorize_resource :course
   load_and_authorize_resource through: :course
@@ -11,11 +12,9 @@ def show
     @assignment = @assignment.decorate
   end
 
-  def new
-  end
+  def new; end
 
-  def edit
-  end
+  def edit; end
 
   def index
     redirect_to @course
diff --git a/app/controllers/confirmations_controller.rb b/app/controllers/confirmations_controller.rb
index e42fbc0f..076c5ad8 100644
--- a/app/controllers/confirmations_controller.rb
+++ b/app/controllers/confirmations_controller.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class ConfirmationsController < Devise::ConfirmationsController
   # Signin automatically if they come in through the link
   def show
diff --git a/app/controllers/courses_controller.rb b/app/controllers/courses_controller.rb
index 8bff0b7b..677ff771 100644
--- a/app/controllers/courses_controller.rb
+++ b/app/controllers/courses_controller.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CoursesController < ApplicationController
   load_and_authorize_resource
 
@@ -17,8 +18,7 @@ def show
     @course = @course.decorate
   end
 
-  def edit
-  end
+  def edit; end
 
   def create
     if @course.update_attributes(course_params)
diff --git a/app/controllers/enrollments_controller.rb b/app/controllers/enrollments_controller.rb
index c0f59835..8e5dad33 100644
--- a/app/controllers/enrollments_controller.rb
+++ b/app/controllers/enrollments_controller.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class EnrollmentsController < ApplicationController
   load_and_authorize_resource class: 'Membership'
 
diff --git a/app/controllers/github_webhooks_controller.rb b/app/controllers/github_webhooks_controller.rb
index afa6cec2..1f6877a6 100644
--- a/app/controllers/github_webhooks_controller.rb
+++ b/app/controllers/github_webhooks_controller.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # app/controllers/github_webhooks_controller.rb
 class GithubWebhooksController < ActionController::Base
   protect_from_forgery
diff --git a/app/controllers/omniauth_callbacks_controller.rb b/app/controllers/omniauth_callbacks_controller.rb
index f48b9992..0823b94c 100644
--- a/app/controllers/omniauth_callbacks_controller.rb
+++ b/app/controllers/omniauth_callbacks_controller.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class OmniauthCallbacksController < Devise::OmniauthCallbacksController
   def facebook
     generic_callback('facebook')
@@ -51,7 +52,7 @@ def user
   end
 
   def set_user_fields
-    [:email, :name].each do |attr|
+    %i[email name].each do |attr|
       user_value = user.send(attr)
       identity_value = identity.send(attr)
 
diff --git a/app/controllers/registrations_controller.rb b/app/controllers/registrations_controller.rb
index d60fc61e..f57d5982 100644
--- a/app/controllers/registrations_controller.rb
+++ b/app/controllers/registrations_controller.rb
@@ -1,9 +1,10 @@
 # frozen_string_literal: true
+
 class RegistrationsController < Devise::RegistrationsController
   def update_resource(resource, params)
     if resource.encrypted_password.blank? # || params[:password].blank?
       resource.email = params[:email] if params[:email]
-      if !params[:password].blank? && params[:password] == params[:password_confirmation]
+      if params[:password].present? && params[:password] == params[:password_confirmation]
         logger.info 'Updating password'
         resource.password = params[:password]
         resource.save
diff --git a/app/controllers/setup_controller.rb b/app/controllers/setup_controller.rb
index b6cb2d8e..91149e74 100644
--- a/app/controllers/setup_controller.rb
+++ b/app/controllers/setup_controller.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rdiscount'
 class SetupController < ApplicationController
   skip_authorization_check
diff --git a/app/controllers/submissions_controller.rb b/app/controllers/submissions_controller.rb
index 7c49773d..453f8362 100644
--- a/app/controllers/submissions_controller.rb
+++ b/app/controllers/submissions_controller.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class SubmissionsController < ApplicationController
   before_action :normalize_params
 
diff --git a/app/controllers/teams_controller.rb b/app/controllers/teams_controller.rb
index 0016a477..7dca635e 100644
--- a/app/controllers/teams_controller.rb
+++ b/app/controllers/teams_controller.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class TeamsController < ApplicationController
   load_and_authorize_resource :assignment
   load_and_authorize_resource through: :assignment
@@ -9,14 +10,11 @@ def page_title
     'Teams'
   end
 
-  def new
-  end
+  def new; end
 
-  def index
-  end
+  def index; end
 
-  def edit
-  end
+  def edit; end
 
   def update
     if @team.update_attributes(team_params)
diff --git a/app/controllers/tests_controller.rb b/app/controllers/tests_controller.rb
index d7e7d717..926c9329 100644
--- a/app/controllers/tests_controller.rb
+++ b/app/controllers/tests_controller.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class TestsController < ApplicationController
   before_action :normalize_params
 
@@ -15,8 +16,7 @@ def new
     cast_test
   end
 
-  def edit
-  end
+  def edit; end
 
   def index
     @tests = @assignment.tests
diff --git a/app/decorators/assignment_decorator.rb b/app/decorators/assignment_decorator.rb
index 4c4f8290..d32878d8 100644
--- a/app/decorators/assignment_decorator.rb
+++ b/app/decorators/assignment_decorator.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AssignmentDecorator < Draper::Decorator
   delegate_all
 
diff --git a/app/decorators/course_decorator.rb b/app/decorators/course_decorator.rb
index a06274a8..4b950af9 100644
--- a/app/decorators/course_decorator.rb
+++ b/app/decorators/course_decorator.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CourseDecorator < Draper::Decorator
   delegate_all
 
diff --git a/app/decorators/file_submission_decorator.rb b/app/decorators/file_submission_decorator.rb
index d9963062..9c37cafb 100644
--- a/app/decorators/file_submission_decorator.rb
+++ b/app/decorators/file_submission_decorator.rb
@@ -1,10 +1,11 @@
 # frozen_string_literal: true
+
 class FileSubmissionDecorator < SubmissionDecorator
   delegate_all
 
   def attributes
-    [:status, :uploaded_by, :created_at, :team_members, :file_size,
-     :download_url, :human_readable_language]
+    %i[status uploaded_by created_at team_members file_size
+       download_url human_readable_language]
   end
 
   def human_readable_language
diff --git a/app/decorators/git_submission_decorator.rb b/app/decorators/git_submission_decorator.rb
index 9d13d1a6..e4359f10 100644
--- a/app/decorators/git_submission_decorator.rb
+++ b/app/decorators/git_submission_decorator.rb
@@ -1,10 +1,11 @@
 # frozen_string_literal: true
+
 class GitSubmissionDecorator < SubmissionDecorator
   delegate_all
 
   def attributes
-    [:status, :uploaded_by, :created_at, :git_repository_url, :git_commit_sha,
-     :git_commit_message, :contributor_names, :team_members]
+    %i[status uploaded_by created_at git_repository_url git_commit_sha
+       git_commit_message contributor_names team_members]
   end
 
   def git_repository_url
diff --git a/app/decorators/submission_decorator.rb b/app/decorators/submission_decorator.rb
index 43e382cc..11b49f13 100644
--- a/app/decorators/submission_decorator.rb
+++ b/app/decorators/submission_decorator.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class SubmissionDecorator < Draper::Decorator
   delegate_all
 
diff --git a/app/decorators/team_decorator.rb b/app/decorators/team_decorator.rb
index 23092bd4..b19f310b 100644
--- a/app/decorators/team_decorator.rb
+++ b/app/decorators/team_decorator.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class TeamDecorator < Draper::Decorator
   delegate_all
 
diff --git a/app/decorators/test_decorator.rb b/app/decorators/test_decorator.rb
index 99132fe8..9659a129 100644
--- a/app/decorators/test_decorator.rb
+++ b/app/decorators/test_decorator.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class TestDecorator < Draper::Decorator
   delegate_all
 
diff --git a/app/decorators/test_result_decorator.rb b/app/decorators/test_result_decorator.rb
index 93548a25..2ee4ce3c 100644
--- a/app/decorators/test_result_decorator.rb
+++ b/app/decorators/test_result_decorator.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class TestResultDecorator < Draper::Decorator
   delegate_all
 
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 9b898a03..504901d6 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 module ApplicationHelper
   # Bootstrap 3 alert classes for flash hash in application layout.
   def flash_class(level)
diff --git a/app/jobs/application_job.rb b/app/jobs/application_job.rb
index 32fe70b8..d92ffddc 100644
--- a/app/jobs/application_job.rb
+++ b/app/jobs/application_job.rb
@@ -1,3 +1,4 @@
 # frozen_string_literal: true
+
 class ApplicationJob < ActiveJob::Base
 end
diff --git a/app/mailers/application_mailer.rb b/app/mailers/application_mailer.rb
index 4447eb4a..df108f2f 100644
--- a/app/mailers/application_mailer.rb
+++ b/app/mailers/application_mailer.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class ApplicationMailer < ActionMailer::Base
   default from: 'ruben+alphgrader@fireservicerota.com'
   layout 'mailer'
diff --git a/app/models/ability.rb b/app/models/ability.rb
index bf40d0ff..3043878f 100644
--- a/app/models/ability.rb
+++ b/app/models/ability.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class Ability
   include CanCan::Ability
   attr_accessor :user
@@ -6,7 +7,7 @@ class Ability
   def initialize(user)
     return if user.nil?
     @user = user
-    can :manage, :all if user && user.admin?
+    can :manage, :all if user&.admin?
 
     setup_course_rights
     setup_assignment_rights
@@ -23,31 +24,31 @@ def setup_course_rights
     can :read, Course, membership_params
     can :create, Course if user.instructor? || user.admin?
 
-    can [:edit, :update, :duplicate], Course, instructor_membership_params
+    can %i[edit update duplicate], Course, instructor_membership_params
   end
 
   def setup_assignment_rights
     can :read, Assignment, course: { memberships: { user_id: user.id } }
-    can [:create, :edit, :update], Assignment, course: instructor_membership_params
+    can %i[create edit update], Assignment, course: instructor_membership_params
   end
 
   def setup_test_rights
     can :read, Test, public: true, assignment: { course: membership_params }
     can :read, Test, public: false, assignment: { course: instructor_membership_params }
-    can [:create, :edit, :update, :destroy], Test, assignment: { course: instructor_membership_params }
+    can %i[create edit update destroy], Test, assignment: { course: instructor_membership_params }
   end
 
   def setup_submission_rights
     can :read, Submission, team: membership_params
     can :read, Submission, assignment: { course_id: instructor_course_ids }
-    can [:new, :create], Submission, assignment: { course: membership_params }
+    can %i[new create], Submission, assignment: { course: membership_params }
   end
 
   def setup_team_rights
     can [:read], Team, memberships: { user_id: user.id }
-    can [:edit, :update], Team, repository_owner_id: user.id
-    can [:read, :edit, :update], Team, assignment: { course_id: instructor_course_ids }
-    can [:new, :create], Team, assignment: { course: membership_params }
+    can %i[edit update], Team, repository_owner_id: user.id
+    can %i[read edit update], Team, assignment: { course_id: instructor_course_ids }
+    can %i[new create], Team, assignment: { course: membership_params }
   end
 
   def instructor_course_ids
diff --git a/app/models/application_record.rb b/app/models/application_record.rb
index 767a072b..71fbba5b 100644
--- a/app/models/application_record.rb
+++ b/app/models/application_record.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class ApplicationRecord < ActiveRecord::Base
   self.abstract_class = true
 end
diff --git a/app/models/assignment.rb b/app/models/assignment.rb
index 6ea6951e..b871e6eb 100644
--- a/app/models/assignment.rb
+++ b/app/models/assignment.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class Assignment < ApplicationRecord
   belongs_to :course, dependent: :destroy, inverse_of: :assignments
   has_many :submissions, dependent: :destroy, inverse_of: :assignment
diff --git a/app/models/author_contribution_test.rb b/app/models/author_contribution_test.rb
index 8e380f47..4bff6894 100644
--- a/app/models/author_contribution_test.rb
+++ b/app/models/author_contribution_test.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AuthorContributionTest < Test
   def self.description
     [:author_contribution_test, {
diff --git a/app/models/author_contribution_test_result.rb b/app/models/author_contribution_test_result.rb
index ec61906d..09eb3dc4 100644
--- a/app/models/author_contribution_test_result.rb
+++ b/app/models/author_contribution_test_result.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AuthorContributionTestResult < TestResult
   def test_type
     AuthorContributionTest
diff --git a/app/models/contribution.rb b/app/models/contribution.rb
index 9e9f3798..c062b187 100644
--- a/app/models/contribution.rb
+++ b/app/models/contribution.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class Contribution < ApplicationRecord
   belongs_to :membership, inverse_of: :contributions
   belongs_to :submission, inverse_of: :contributions
diff --git a/app/models/course.rb b/app/models/course.rb
index 3c62718a..3dab02a6 100644
--- a/app/models/course.rb
+++ b/app/models/course.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class Course < ApplicationRecord
   has_many :memberships, dependent: :destroy
   has_many :users, through: :memberships
diff --git a/app/models/expected_output_test.rb b/app/models/expected_output_test.rb
index cd2211d1..9911490f 100644
--- a/app/models/expected_output_test.rb
+++ b/app/models/expected_output_test.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class ExpectedOutputTest < OutputTest
   def self.description
     [:expected_output_test, {
diff --git a/app/models/expected_output_test_result.rb b/app/models/expected_output_test_result.rb
index 2682f131..252d1501 100644
--- a/app/models/expected_output_test_result.rb
+++ b/app/models/expected_output_test_result.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class ExpectedOutputTestResult < TestResult
   def test_type
     ExpectedOutputTest
diff --git a/app/models/expected_output_test_runner.rb b/app/models/expected_output_test_runner.rb
index 94eeeaec..0279df92 100644
--- a/app/models/expected_output_test_runner.rb
+++ b/app/models/expected_output_test_runner.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class ExpectedOutputTestRunner < OutputTestRunner
   def correct_output?
     clean_string(expected_program_output) == clean_string(output)
diff --git a/app/models/file_submission.rb b/app/models/file_submission.rb
index 7edd3e41..3ec23eed 100644
--- a/app/models/file_submission.rb
+++ b/app/models/file_submission.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class FileSubmission < Submission
   validates :file, presence: true
   has_attached_file :file
diff --git a/app/models/git_submission.rb b/app/models/git_submission.rb
index 3654521c..a7e4da76 100644
--- a/app/models/git_submission.rb
+++ b/app/models/git_submission.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class GitSubmission < Submission
   validates :github_repository_name, presence: true
 
diff --git a/app/models/google_apps_client.rb b/app/models/google_apps_client.rb
index 5748684a..f18078cf 100644
--- a/app/models/google_apps_client.rb
+++ b/app/models/google_apps_client.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class GoogleAppsClient
   def initialize(client)
     @client = client
diff --git a/app/models/identity.rb b/app/models/identity.rb
index b8a2bc59..454d16ee 100644
--- a/app/models/identity.rb
+++ b/app/models/identity.rb
@@ -1,5 +1,6 @@
 # frozen_string_literal: true
-class Identity < ActiveRecord::Base
+
+class Identity < ApplicationRecord
   belongs_to :user, required: false
   validates :uid, :provider, presence: true
   validates :uid, uniqueness: { scope: :provider }
diff --git a/app/models/membership.rb b/app/models/membership.rb
index a81e315e..d0a84787 100644
--- a/app/models/membership.rb
+++ b/app/models/membership.rb
@@ -1,10 +1,11 @@
 # frozen_string_literal: true
+
 class Membership < ApplicationRecord
   belongs_to :user
   belongs_to :course
   has_and_belongs_to_many :teams
 
-  enum role: [:student, :instructor]
+  enum role: %i[student instructor]
 
   attr_accessor :enrollment_code
 
diff --git a/app/models/output_test.rb b/app/models/output_test.rb
index 7df7ddc6..17c0c555 100644
--- a/app/models/output_test.rb
+++ b/app/models/output_test.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class OutputTest < Test
   validates :expected_program_output, presence: true
   validates :program_input, presence: true
diff --git a/app/models/output_test_runner.rb b/app/models/output_test_runner.rb
index f3a5612c..5ae29494 100644
--- a/app/models/output_test_runner.rb
+++ b/app/models/output_test_runner.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class OutputTestRunner
   TIME_LIMIT = 30
 
diff --git a/app/models/regexp_output_test.rb b/app/models/regexp_output_test.rb
index b8214722..22c238fb 100644
--- a/app/models/regexp_output_test.rb
+++ b/app/models/regexp_output_test.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class RegexpOutputTest < OutputTest
   def self.description
     [:regexp_output_test, {
diff --git a/app/models/regexp_output_test_runner.rb b/app/models/regexp_output_test_runner.rb
index 470d94b0..72f13725 100644
--- a/app/models/regexp_output_test_runner.rb
+++ b/app/models/regexp_output_test_runner.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class RegexpOutputTestRunner < OutputTestRunner
   def correct_output?
     regexp = Regexp.new expected_program_output
diff --git a/app/models/required_file_test.rb b/app/models/required_file_test.rb
index 5db9570c..70ccf16d 100644
--- a/app/models/required_file_test.rb
+++ b/app/models/required_file_test.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class RequiredFileTest < Test
   validates :filename, presence: true
 
diff --git a/app/models/required_file_test_result.rb b/app/models/required_file_test_result.rb
index 8b5481b3..6c0cd448 100644
--- a/app/models/required_file_test_result.rb
+++ b/app/models/required_file_test_result.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class RequiredFileTestResult < TestResult
   def test_type
     RequiredFileTest
diff --git a/app/models/submission.rb b/app/models/submission.rb
index 9a6b6efb..1d82fe3a 100644
--- a/app/models/submission.rb
+++ b/app/models/submission.rb
@@ -1,10 +1,11 @@
 # frozen_string_literal: true
+
 class Submission < ApplicationRecord
   belongs_to :assignment
   belongs_to :uploaded_by, class_name: 'User'
   belongs_to :team, inverse_of: :submissions
 
-  enum status: [:queued, :running, :success, :failure]
+  enum status: %i[queued running success failure]
   has_many :test_results, dependent: :destroy
   has_many :contributions, inverse_of: :submission, dependent: :destroy
   has_many :contributors, through: :contributions, class_name: 'Membership', source: :membership
@@ -26,8 +27,7 @@ def detect_status
     self.status = test_results.reload.all?(&:success?) ? :success : :failure
   end
 
-  def download
-  end
+  def download; end
 
   def run_tests
     test_results.destroy_all
@@ -73,8 +73,7 @@ def notify_users
     end
   end
 
-  def run_pre_test_checks
-  end
+  def run_pre_test_checks; end
 
   def run_user_tests
     assignment.tests.each do |test|
diff --git a/app/models/team.rb b/app/models/team.rb
index ba3f92d3..89161a4b 100644
--- a/app/models/team.rb
+++ b/app/models/team.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class Team < ApplicationRecord
   belongs_to :assignment, inverse_of: :teams
 
diff --git a/app/models/test.rb b/app/models/test.rb
index 6133c537..53346733 100644
--- a/app/models/test.rb
+++ b/app/models/test.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class Test < ApplicationRecord
   belongs_to :assignment
   has_many :test_results
diff --git a/app/models/test_result.rb b/app/models/test_result.rb
index 07a90b09..5d00f271 100644
--- a/app/models/test_result.rb
+++ b/app/models/test_result.rb
@@ -1,7 +1,8 @@
 # frozen_string_literal: true
+
 class TestResult < ApplicationRecord
   belongs_to :test
   belongs_to :submission
 
-  enum status: [:success, :failure, :error]
+  enum status: %i[success failure error]
 end
diff --git a/app/models/user.rb b/app/models/user.rb
index 0e29ea7b..cbb04975 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class User < ApplicationRecord
   attr_accessor :oauth_callback
   attr_accessor :current_password
@@ -34,7 +35,7 @@ def email_required?
   end
 
   has_many :identities, dependent: :destroy
-  enum role: [:user, :admin, :instructor]
+  enum role: %i[user admin instructor]
   # Include default devise modules. Others available are:
   # :confirmable, :lockable, :timeoutable and :omniauthable
   devise :confirmable, :database_authenticatable, :registerable,
diff --git a/app/workers/submission_check_worker.rb b/app/workers/submission_check_worker.rb
index 91078585..706f2253 100644
--- a/app/workers/submission_check_worker.rb
+++ b/app/workers/submission_check_worker.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class SubmissionCheckWorker
   include Sidekiq::Worker
   sidekiq_options queue: 'high'
diff --git a/bin/bundle b/bin/bundle
index 86f34665..58115ecf 100755
--- a/bin/bundle
+++ b/bin/bundle
@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
+
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
 load Gem.bin_path('bundler', 'bundle')
diff --git a/bin/rails b/bin/rails
index dd027b40..a31728ab 100755
--- a/bin/rails
+++ b/bin/rails
@@ -1,5 +1,6 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
+
 APP_PATH = File.expand_path('../config/application', __dir__)
 require_relative '../config/boot'
 require 'rails/commands'
diff --git a/bin/rake b/bin/rake
index 609af747..c1999550 100755
--- a/bin/rake
+++ b/bin/rake
@@ -1,5 +1,6 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
+
 require_relative '../config/boot'
 require 'rake'
 Rake.application.run
diff --git a/bin/rspec b/bin/rspec
index 9d4b897d..5e0951ea 100755
--- a/bin/rspec
+++ b/bin/rspec
@@ -1,5 +1,6 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
+
 begin
   load File.expand_path('../spring', __FILE__)
 rescue LoadError => e
diff --git a/bin/setup b/bin/setup
index ffca742a..629e3584 100755
--- a/bin/setup
+++ b/bin/setup
@@ -1,5 +1,6 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
+
 require 'pathname'
 require 'fileutils'
 include FileUtils
diff --git a/bin/update b/bin/update
index 3f81e549..fdac831b 100755
--- a/bin/update
+++ b/bin/update
@@ -1,5 +1,6 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
+
 require 'pathname'
 require 'fileutils'
 include FileUtils
diff --git a/config.ru b/config.ru
index 7eae2644..842bccc3 100644
--- a/config.ru
+++ b/config.ru
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # This file is used by Rack-based servers to start the application.
 
 require_relative 'config/environment'
diff --git a/config/application.rb b/config/application.rb
index a77a7a01..85460a1d 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require_relative 'boot'
 
 require 'rails/all'
diff --git a/config/boot.rb b/config/boot.rb
index 9be337a4..30e594e2 100644
--- a/config/boot.rb
+++ b/config/boot.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 
 require 'bundler/setup' # Set up gems listed in the Gemfile.
diff --git a/config/breadcrumbs.rb b/config/breadcrumbs.rb
index a1c08563..67ef2e2e 100644
--- a/config/breadcrumbs.rb
+++ b/config/breadcrumbs.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 crumb :root do
   link 'Home', root_path
 end
@@ -14,18 +15,14 @@
 end
 
 crumb :assignment do |assignment|
-  url = if assignment.persisted?
-          course_assignment_path(assignment.course, assignment)
-        end
+  url = (course_assignment_path(assignment.course, assignment) if assignment.persisted?)
   text = assignment.name || 'New Assignment'
   link text, url
   parent :course, assignment.course
 end
 
 crumb :submission do |submission|
-  url = if submission.persisted?
-          assignment_submission_path(submission.assignment, submission)
-        end
+  url = (assignment_submission_path(submission.assignment, submission) if submission.persisted?)
   text = submission.decorate.created_at || 'New Submission'
   link text, url
   parent :assignment, submission.assignment
diff --git a/config/deploy/staging.rb b/config/deploy/staging.rb
index 80dc5a5e..5437e5d3 100644
--- a/config/deploy/staging.rb
+++ b/config/deploy/staging.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 set :stage, :staging
 set :rails_env, fetch(:stage) # set the rails environment
 
diff --git a/config/environment.rb b/config/environment.rb
index dcc7adec..1f56dcc8 100644
--- a/config/environment.rb
+++ b/config/environment.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Load the Rails application.
 require_relative 'application'
 
diff --git a/config/environments/development.rb b/config/environments/development.rb
index 20913675..e4e20840 100644
--- a/config/environments/development.rb
+++ b/config/environments/development.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
diff --git a/config/environments/production.rb b/config/environments/production.rb
index 00fa1c7f..a5c908d0 100644
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
diff --git a/config/environments/test.rb b/config/environments/test.rb
index 416a71c8..5344748c 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
diff --git a/config/initializers/active_admin.rb b/config/initializers/active_admin.rb
index 930a2ced..63e573c2 100644
--- a/config/initializers/active_admin.rb
+++ b/config/initializers/active_admin.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 ActiveAdmin.setup do |config|
   # == Site Title
   #
diff --git a/config/initializers/assets.rb b/config/initializers/assets.rb
index 74fbcb9e..b31e368d 100644
--- a/config/initializers/assets.rb
+++ b/config/initializers/assets.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Version of your assets, change this if you want to expire all your assets.
@@ -11,4 +12,4 @@
 # application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
 # Rails.application.config.assets.precompile += %w( search.js )
 
-Rails.application.config.assets.precompile += %w(chartkick.js)
+Rails.application.config.assets.precompile += %w[chartkick.js]
diff --git a/config/initializers/cookies_serializer.rb b/config/initializers/cookies_serializer.rb
index 2a729595..ee8dff9c 100644
--- a/config/initializers/cookies_serializer.rb
+++ b/config/initializers/cookies_serializer.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Specify a serializer for the signed and encrypted cookie jars.
diff --git a/config/initializers/devise.rb b/config/initializers/devise.rb
index fe984860..e7c15940 100644
--- a/config/initializers/devise.rb
+++ b/config/initializers/devise.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Use this hook to configure devise mailer, warden hooks and so forth.
 # Many of these configuration options can be set straight in your model.
 Devise.setup do |config|
diff --git a/config/initializers/errbit.rb b/config/initializers/errbit.rb
index 2e309ddc..a1c00ede 100644
--- a/config/initializers/errbit.rb
+++ b/config/initializers/errbit.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 Airbrake.configure do |config|
   config.api_key = ENV.fetch('AIRBRAKE_API_KEY')
   config.host    = ENV.fetch('AIRBRAKE_HOST')
diff --git a/config/initializers/filter_parameter_logging.rb b/config/initializers/filter_parameter_logging.rb
index b7fe1231..7a4f47b4 100644
--- a/config/initializers/filter_parameter_logging.rb
+++ b/config/initializers/filter_parameter_logging.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Configure sensitive parameters which will be filtered from the log file.
diff --git a/config/initializers/haml.rb b/config/initializers/haml.rb
index 844fe7bc..d2c02637 100644
--- a/config/initializers/haml.rb
+++ b/config/initializers/haml.rb
@@ -1,2 +1,3 @@
 # frozen_string_literal: true
+
 Haml::Template.options[:ugly] = true
diff --git a/config/initializers/jazz_hands.rb b/config/initializers/jazz_hands.rb
index d714e003..08464673 100644
--- a/config/initializers/jazz_hands.rb
+++ b/config/initializers/jazz_hands.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 if defined?(JazzHands)
   JazzHands.colored_prompt = true
   # Uncomment for MRI 1.9.3 or 2.0.0
diff --git a/config/initializers/new_framework_defaults.rb b/config/initializers/new_framework_defaults.rb
index 0f337889..050fcec3 100644
--- a/config/initializers/new_framework_defaults.rb
+++ b/config/initializers/new_framework_defaults.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 #
 # This file contains migration options to ease your Rails 5.0 upgrade.
diff --git a/config/initializers/paperclip.rb b/config/initializers/paperclip.rb
index fb9b2a46..6a4c2e59 100644
--- a/config/initializers/paperclip.rb
+++ b/config/initializers/paperclip.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 Paperclip::Attachment.default_options[:storage] = :s3
 Paperclip::Attachment.default_options[:s3_credentials] =
   "#{Rails.root}/config/amazon_s3.yml"
diff --git a/config/initializers/session_store.rb b/config/initializers/session_store.rb
index c0b021e9..bc661b6e 100644
--- a/config/initializers/session_store.rb
+++ b/config/initializers/session_store.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 Rails.application.config.session_store :cookie_store, key: '_alphagrader_session'
diff --git a/config/initializers/sidekiq.rb b/config/initializers/sidekiq.rb
index d08401e1..d11fd8bd 100644
--- a/config/initializers/sidekiq.rb
+++ b/config/initializers/sidekiq.rb
@@ -9,7 +9,7 @@
 Sidekiq.options[:poll_interval] = 2
 
 Sidekiq.configure_server do |config|
-  sidekiq_config = YAML.load(File.new("#{Rails.root}/config/sidekiq.yml"))
+  sidekiq_config = YAML.safe_load(File.new("#{Rails.root}/config/sidekiq.yml"))
   config.redis = redis_config
   schedule_file = 'config/sidekiq_schedule.yml'
 
@@ -25,9 +25,7 @@
     ActiveRecord::Base.establish_connection(config)
   end
 
-  if File.exist?(schedule_file) && Sidekiq.server?
-    Sidekiq::Cron::Job.load_from_hash! YAML.load_file(schedule_file)
-  end
+  Sidekiq::Cron::Job.load_from_hash! YAML.load_file(schedule_file) if File.exist?(schedule_file) && Sidekiq.server?
 end
 
 Sidekiq.configure_client do |config|
diff --git a/config/initializers/simple_form.rb b/config/initializers/simple_form.rb
index 4e7dbabc..3f45ec8a 100644
--- a/config/initializers/simple_form.rb
+++ b/config/initializers/simple_form.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Use this setup block to configure all options available in SimpleForm.
 SimpleForm.setup do |config|
   # Wrappers are used by the form builder to generate a
diff --git a/config/initializers/simple_form_bootstrap.rb b/config/initializers/simple_form_bootstrap.rb
index c1247278..9b51a9d5 100644
--- a/config/initializers/simple_form_bootstrap.rb
+++ b/config/initializers/simple_form_bootstrap.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Use this setup block to configure all options available in SimpleForm.
 SimpleForm.setup do |config|
   config.error_notification_class = 'alert alert-danger'
diff --git a/config/initializers/warden_hooks.rb b/config/initializers/warden_hooks.rb
index 0f5325d9..e1ee13dc 100644
--- a/config/initializers/warden_hooks.rb
+++ b/config/initializers/warden_hooks.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 Warden::Manager.after_set_user do |user, auth, opts|
   scope = opts[:scope]
   auth.cookies.signed["#{scope}.id"] = user.id
diff --git a/config/initializers/wrap_parameters.rb b/config/initializers/wrap_parameters.rb
index 18c38252..2f3c0db4 100644
--- a/config/initializers/wrap_parameters.rb
+++ b/config/initializers/wrap_parameters.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # This file contains settings for ActionController::ParamsWrapper which
diff --git a/config/puma.rb b/config/puma.rb
index da41eff9..03a28243 100644
--- a/config/puma.rb
+++ b/config/puma.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Puma can serve each request in a thread from an internal thread pool.
 # The `threads` method setting takes two numbers a minimum and maximum.
 # Any libraries that use thread pools should be configured to match
diff --git a/config/spring.rb b/config/spring.rb
index 312295f4..c5933e49 100644
--- a/config/spring.rb
+++ b/config/spring.rb
@@ -1,7 +1,8 @@
 # frozen_string_literal: true
-%w(
+
+%w[
   .ruby-version
   .rbenv-vars
   tmp/restart.txt
   tmp/caching-dev.txt
-).each { |path| Spring.watch(path) }
+].each { |path| Spring.watch(path) }
diff --git a/db/migrate/20170102233353_devise_create_users.rb b/db/migrate/20170102233353_devise_create_users.rb
index 160c8914..51252ffe 100644
--- a/db/migrate/20170102233353_devise_create_users.rb
+++ b/db/migrate/20170102233353_devise_create_users.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class DeviseCreateUsers < ActiveRecord::Migration[5.0]
   def change
     create_table :users do |t|
diff --git a/db/migrate/20170102233404_add_role_to_users.rb b/db/migrate/20170102233404_add_role_to_users.rb
index 23dc2f36..bd093353 100644
--- a/db/migrate/20170102233404_add_role_to_users.rb
+++ b/db/migrate/20170102233404_add_role_to_users.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddRoleToUsers < ActiveRecord::Migration[5.0]
   def change
     add_column :users, :role, :integer
diff --git a/db/migrate/20170102233429_add_confirmable_to_devise.rb b/db/migrate/20170102233429_add_confirmable_to_devise.rb
index d5a8435e..16141f69 100644
--- a/db/migrate/20170102233429_add_confirmable_to_devise.rb
+++ b/db/migrate/20170102233429_add_confirmable_to_devise.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddConfirmableToDevise < ActiveRecord::Migration
   # Note: You can't use change, as User.update_all will fail in the down migration
   def up
diff --git a/db/migrate/20170102233435_make_email_nullable.rb b/db/migrate/20170102233435_make_email_nullable.rb
index 4e6bb2b7..e4906e54 100644
--- a/db/migrate/20170102233435_make_email_nullable.rb
+++ b/db/migrate/20170102233435_make_email_nullable.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class MakeEmailNullable < ActiveRecord::Migration
   def change
     change_column_null :users, :email, true
diff --git a/db/migrate/20170102233502_create_identities.rb b/db/migrate/20170102233502_create_identities.rb
index 930d7c8c..aa54ba41 100644
--- a/db/migrate/20170102233502_create_identities.rb
+++ b/db/migrate/20170102233502_create_identities.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CreateIdentities < ActiveRecord::Migration[5.0]
   def change
     create_table :identities do |t|
diff --git a/db/migrate/20170102233738_add_refresh_token_to_identity.rb b/db/migrate/20170102233738_add_refresh_token_to_identity.rb
index 295a0cea..99ecf8bc 100644
--- a/db/migrate/20170102233738_add_refresh_token_to_identity.rb
+++ b/db/migrate/20170102233738_add_refresh_token_to_identity.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddRefreshTokenToIdentity < ActiveRecord::Migration
   def change
     add_column :identities, :refreshtoken, :string
diff --git a/db/migrate/20170102233955_add_secret_token_to_identity.rb b/db/migrate/20170102233955_add_secret_token_to_identity.rb
index 4a5dd3e0..eb26c652 100644
--- a/db/migrate/20170102233955_add_secret_token_to_identity.rb
+++ b/db/migrate/20170102233955_add_secret_token_to_identity.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddSecretTokenToIdentity < ActiveRecord::Migration
   def change
     add_column :identities, :secrettoken, :string
diff --git a/db/migrate/20170102234223_create_active_admin_comments.rb b/db/migrate/20170102234223_create_active_admin_comments.rb
index 35d5aff1..72363ab0 100644
--- a/db/migrate/20170102234223_create_active_admin_comments.rb
+++ b/db/migrate/20170102234223_create_active_admin_comments.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CreateActiveAdminComments < ActiveRecord::Migration
   def self.up
     create_table :active_admin_comments do |t|
@@ -10,8 +11,8 @@ def self.up
       t.timestamps
     end
     add_index :active_admin_comments, [:namespace]
-    add_index :active_admin_comments, [:author_type, :author_id]
-    add_index :active_admin_comments, [:resource_type, :resource_id]
+    add_index :active_admin_comments, %i[author_type author_id]
+    add_index :active_admin_comments, %i[resource_type resource_id]
   end
 
   def self.down
diff --git a/db/migrate/20170103040210_create_courses.rb b/db/migrate/20170103040210_create_courses.rb
index b8cb48be..cac81645 100644
--- a/db/migrate/20170103040210_create_courses.rb
+++ b/db/migrate/20170103040210_create_courses.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CreateCourses < ActiveRecord::Migration[5.0]
   def change
     create_table :courses do |t|
diff --git a/db/migrate/20170103040551_create_memberships.rb b/db/migrate/20170103040551_create_memberships.rb
index 7585c389..836961eb 100644
--- a/db/migrate/20170103040551_create_memberships.rb
+++ b/db/migrate/20170103040551_create_memberships.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CreateMemberships < ActiveRecord::Migration[5.0]
   def change
     create_table :memberships do |t|
diff --git a/db/migrate/20170103051554_add_name_to_user.rb b/db/migrate/20170103051554_add_name_to_user.rb
index d1b500b4..72db84a6 100644
--- a/db/migrate/20170103051554_add_name_to_user.rb
+++ b/db/migrate/20170103051554_add_name_to_user.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddNameToUser < ActiveRecord::Migration[5.0]
   def change
     add_column :users, :name, :string
diff --git a/db/migrate/20170103052630_create_assignments.rb b/db/migrate/20170103052630_create_assignments.rb
index 869c58c3..37dd5a20 100644
--- a/db/migrate/20170103052630_create_assignments.rb
+++ b/db/migrate/20170103052630_create_assignments.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CreateAssignments < ActiveRecord::Migration[5.0]
   def change
     create_table :assignments do |t|
diff --git a/db/migrate/20170103061109_create_submissions.rb b/db/migrate/20170103061109_create_submissions.rb
index 44f0a36b..5beabb63 100644
--- a/db/migrate/20170103061109_create_submissions.rb
+++ b/db/migrate/20170103061109_create_submissions.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CreateSubmissions < ActiveRecord::Migration[5.0]
   def change
     create_table :submissions do |t|
diff --git a/db/migrate/20170103063306_create_author_submission_join_table.rb b/db/migrate/20170103063306_create_author_submission_join_table.rb
index 178f6cac..93e84e2f 100644
--- a/db/migrate/20170103063306_create_author_submission_join_table.rb
+++ b/db/migrate/20170103063306_create_author_submission_join_table.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CreateAuthorSubmissionJoinTable < ActiveRecord::Migration[5.0]
   def change
     create_table :author_submissions, id: false do |t|
diff --git a/db/migrate/20170104043110_add_unique_index_to_membership.rb b/db/migrate/20170104043110_add_unique_index_to_membership.rb
index 691ea74e..6ec03e52 100644
--- a/db/migrate/20170104043110_add_unique_index_to_membership.rb
+++ b/db/migrate/20170104043110_add_unique_index_to_membership.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
+
 class AddUniqueIndexToMembership < ActiveRecord::Migration[5.0]
   def change
-    add_index :memberships, [:user_id, :course_id], unique: true
+    add_index :memberships, %i[user_id course_id], unique: true
   end
 end
diff --git a/db/migrate/20170104234446_create_tests.rb b/db/migrate/20170104234446_create_tests.rb
index 49aeba76..a97fc0d1 100644
--- a/db/migrate/20170104234446_create_tests.rb
+++ b/db/migrate/20170104234446_create_tests.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CreateTests < ActiveRecord::Migration[5.0]
   def change
     create_table :tests do |t|
diff --git a/db/migrate/20170104235602_create_test_results.rb b/db/migrate/20170104235602_create_test_results.rb
index 43583e50..245f0cdb 100644
--- a/db/migrate/20170104235602_create_test_results.rb
+++ b/db/migrate/20170104235602_create_test_results.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CreateTestResults < ActiveRecord::Migration[5.0]
   def change
     create_table :test_results do |t|
diff --git a/db/migrate/20170105182703_add_commit_message_to_submission.rb b/db/migrate/20170105182703_add_commit_message_to_submission.rb
index 90ff1291..21e52ea7 100644
--- a/db/migrate/20170105182703_add_commit_message_to_submission.rb
+++ b/db/migrate/20170105182703_add_commit_message_to_submission.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddCommitMessageToSubmission < ActiveRecord::Migration[5.0]
   def change
     add_column :submissions, :git_commit_message, :string
diff --git a/db/migrate/20170105184616_add_fields_to_test_results.rb b/db/migrate/20170105184616_add_fields_to_test_results.rb
index 6fd4130f..e2f102de 100644
--- a/db/migrate/20170105184616_add_fields_to_test_results.rb
+++ b/db/migrate/20170105184616_add_fields_to_test_results.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddFieldsToTestResults < ActiveRecord::Migration[5.0]
   def change
     add_column :test_results, :name, :string
diff --git a/db/migrate/20170106003653_add_github_repository_name_to_submission.rb b/db/migrate/20170106003653_add_github_repository_name_to_submission.rb
index cbc2654b..c5cbe21b 100644
--- a/db/migrate/20170106003653_add_github_repository_name_to_submission.rb
+++ b/db/migrate/20170106003653_add_github_repository_name_to_submission.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddGithubRepositoryNameToSubmission < ActiveRecord::Migration[5.0]
   def change
     add_column :submissions, :github_repository_name, :string, index: true
diff --git a/db/migrate/20170108013759_create_teams.rb b/db/migrate/20170108013759_create_teams.rb
index 61b0f055..5ad6ecf5 100644
--- a/db/migrate/20170108013759_create_teams.rb
+++ b/db/migrate/20170108013759_create_teams.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CreateTeams < ActiveRecord::Migration[5.0]
   def change
     create_table :teams do |t|
diff --git a/db/migrate/20170108014805_create_memberships_teams_join_table.rb b/db/migrate/20170108014805_create_memberships_teams_join_table.rb
index 543da330..2466a35f 100644
--- a/db/migrate/20170108014805_create_memberships_teams_join_table.rb
+++ b/db/migrate/20170108014805_create_memberships_teams_join_table.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CreateMembershipsTeamsJoinTable < ActiveRecord::Migration[5.0]
   def change
     create_table :memberships_teams, id: false do |t|
diff --git a/db/migrate/20170108045626_add_team_id_to_submission.rb b/db/migrate/20170108045626_add_team_id_to_submission.rb
index 7ea76648..94252aeb 100644
--- a/db/migrate/20170108045626_add_team_id_to_submission.rb
+++ b/db/migrate/20170108045626_add_team_id_to_submission.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddTeamIdToSubmission < ActiveRecord::Migration[5.0]
   def change
     add_reference :submissions, :team, index: true
diff --git a/db/migrate/20170108202615_create_contributions.rb b/db/migrate/20170108202615_create_contributions.rb
index 90a85fcb..4600eb1c 100644
--- a/db/migrate/20170108202615_create_contributions.rb
+++ b/db/migrate/20170108202615_create_contributions.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class CreateContributions < ActiveRecord::Migration[5.0]
   def change
     create_table :contributions do |t|
diff --git a/db/migrate/20170108202754_drop_author_submissions_join_table.rb b/db/migrate/20170108202754_drop_author_submissions_join_table.rb
index 4daf10a5..7023872b 100644
--- a/db/migrate/20170108202754_drop_author_submissions_join_table.rb
+++ b/db/migrate/20170108202754_drop_author_submissions_join_table.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class DropAuthorSubmissionsJoinTable < ActiveRecord::Migration[5.0]
   def change
     drop_table :author_submissions
diff --git a/db/migrate/20170212050345_add_filename_to_tests.rb b/db/migrate/20170212050345_add_filename_to_tests.rb
index 069f1172..8159ca3c 100644
--- a/db/migrate/20170212050345_add_filename_to_tests.rb
+++ b/db/migrate/20170212050345_add_filename_to_tests.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddFilenameToTests < ActiveRecord::Migration[5.0]
   def change
     add_column :tests, :filename, :string
diff --git a/db/migrate/20170212050815_add_filename_to_test_result.rb b/db/migrate/20170212050815_add_filename_to_test_result.rb
index 253d2579..04395cc5 100644
--- a/db/migrate/20170212050815_add_filename_to_test_result.rb
+++ b/db/migrate/20170212050815_add_filename_to_test_result.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddFilenameToTestResult < ActiveRecord::Migration[5.0]
   def change
     add_column :test_results, :filename, :string
diff --git a/db/migrate/20170213012612_add_file_to_submissions.rb b/db/migrate/20170213012612_add_file_to_submissions.rb
index cfea527a..b86a2ee3 100644
--- a/db/migrate/20170213012612_add_file_to_submissions.rb
+++ b/db/migrate/20170213012612_add_file_to_submissions.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddFileToSubmissions < ActiveRecord::Migration[5.0]
   def change
     add_attachment :submissions, :file
diff --git a/db/migrate/20170301174316_add_error_log_and_timout_to_test_results.rb b/db/migrate/20170301174316_add_error_log_and_timout_to_test_results.rb
index 8e66a98c..5f13f61a 100644
--- a/db/migrate/20170301174316_add_error_log_and_timout_to_test_results.rb
+++ b/db/migrate/20170301174316_add_error_log_and_timout_to_test_results.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddErrorLogAndTimoutToTestResults < ActiveRecord::Migration[5.0]
   def change
     add_column :test_results, :timeout, :boolean, default: false
diff --git a/db/migrate/20170602190751_add_language_to_submission.rb b/db/migrate/20170602190751_add_language_to_submission.rb
index 8fbdc30b..f4afa0c3 100644
--- a/db/migrate/20170602190751_add_language_to_submission.rb
+++ b/db/migrate/20170602190751_add_language_to_submission.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class AddLanguageToSubmission < ActiveRecord::Migration[5.0]
   def change
     add_column :submissions, :language, :string
diff --git a/features/support/env.rb b/features/support/env.rb
index cfa1344a..93a634e8 100644
--- a/features/support/env.rb
+++ b/features/support/env.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # IMPORTANT: This file is generated by cucumber-rails - edit at your own peril.
 # It is recommended to regenerate this file in the future when you upgrade to a
 # newer version of cucumber-rails. Consider adding your own code to a new file
diff --git a/lib/tasks/cucumber.rake b/lib/tasks/cucumber.rake
index e5f3d09a..f34c5789 100644
--- a/lib/tasks/cucumber.rake
+++ b/lib/tasks/cucumber.rake
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # IMPORTANT: This file is generated by cucumber-rails - edit at your own peril.
 # It is recommended to regenerate this file in the future when you upgrade to a
 # newer version of cucumber-rails. Consider adding your own code to a new file
@@ -34,11 +35,11 @@ unless ARGV.any? { |a| a =~ /^gems/ } # Don't load anything when running the gem
       end
 
       desc 'Run all features'
-      task all: [:ok, :wip]
+      task all: %i[ok wip]
 
       task :statsetup do
         require 'rails/code_statistics'
-        ::STATS_DIRECTORIES << %w(Cucumber\ features features) if File.exist?('features')
+        ::STATS_DIRECTORIES << %w[Cucumber\ features features] if File.exist?('features')
         ::CodeStatistics::TEST_TYPES << 'Cucumber features' if File.exist?('features')
       end
 
diff --git a/lib/tasks/haml2erb.rake b/lib/tasks/haml2erb.rake
index 8b418932..a7cafa84 100644
--- a/lib/tasks/haml2erb.rake
+++ b/lib/tasks/haml2erb.rake
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 desc 'Converts everything to erb'
 task :haml2erb do
   require 'httparty'
diff --git a/spec/controllers/admin/stats_controller_spec.rb b/spec/controllers/admin/stats_controller_spec.rb
index e3850e0b..bc78fc9f 100644
--- a/spec/controllers/admin/stats_controller_spec.rb
+++ b/spec/controllers/admin/stats_controller_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 describe Admin::StatsController, type: :controller do
diff --git a/spec/controllers/setup_controller_spec.rb b/spec/controllers/setup_controller_spec.rb
index 035bb6a7..097ef935 100644
--- a/spec/controllers/setup_controller_spec.rb
+++ b/spec/controllers/setup_controller_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 RSpec.describe SetupController, type: :controller do
diff --git a/spec/factories/admin_users.rb b/spec/factories/admin_users.rb
index 86c6fa43..e0c960d6 100644
--- a/spec/factories/admin_users.rb
+++ b/spec/factories/admin_users.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 FactoryGirl.define do
   factory :admin_user, class: 'User' do
     name { Faker::Name.name }
diff --git a/spec/factories/assignments.rb b/spec/factories/assignments.rb
index bec6e913..4f1b21c5 100644
--- a/spec/factories/assignments.rb
+++ b/spec/factories/assignments.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/contributions.rb b/spec/factories/contributions.rb
index 0be9dc41..eab3341c 100644
--- a/spec/factories/contributions.rb
+++ b/spec/factories/contributions.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 FactoryGirl.define do
   factory :contribution do
     membership
diff --git a/spec/factories/courses.rb b/spec/factories/courses.rb
index a9244261..45cab893 100644
--- a/spec/factories/courses.rb
+++ b/spec/factories/courses.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/memberships.rb b/spec/factories/memberships.rb
index f97c51b1..9d09fd4b 100644
--- a/spec/factories/memberships.rb
+++ b/spec/factories/memberships.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/oauth.rb b/spec/factories/oauth.rb
index ace63a35..4d1eb822 100644
--- a/spec/factories/oauth.rb
+++ b/spec/factories/oauth.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 FactoryGirl.define do
   factory :oauth_user, class: 'User' do
     before(:create) do |user, _evaluator|
diff --git a/spec/factories/submissions.rb b/spec/factories/submissions.rb
index 43c834c7..1c0a839a 100644
--- a/spec/factories/submissions.rb
+++ b/spec/factories/submissions.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/teams.rb b/spec/factories/teams.rb
index d219df5c..3783c1e2 100644
--- a/spec/factories/teams.rb
+++ b/spec/factories/teams.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 FactoryGirl.define do
   factory :team do
     github_repository_name { "user_#{SecureRandom.hex}/repo" }
diff --git a/spec/factories/test_result.rb b/spec/factories/test_result.rb
index 4de8f662..f1e9fec9 100644
--- a/spec/factories/test_result.rb
+++ b/spec/factories/test_result.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/tests.rb b/spec/factories/tests.rb
index dd8f043b..edd29df9 100644
--- a/spec/factories/tests.rb
+++ b/spec/factories/tests.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/users.rb b/spec/factories/users.rb
index 4980747b..5f3276a4 100644
--- a/spec/factories/users.rb
+++ b/spec/factories/users.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/features/assignment_spec.rb b/spec/features/assignment_spec.rb
index 7a2b82f2..d8de8a24 100644
--- a/spec/features/assignment_spec.rb
+++ b/spec/features/assignment_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 feature 'Assignment', type: :feature do
diff --git a/spec/features/course_spec.rb b/spec/features/course_spec.rb
index 0af1fda8..0f21eac6 100644
--- a/spec/features/course_spec.rb
+++ b/spec/features/course_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 feature 'Courses', type: :feature do
diff --git a/spec/features/github_registration_spec.rb b/spec/features/github_registration_spec.rb
index 4365a066..478b2bca 100644
--- a/spec/features/github_registration_spec.rb
+++ b/spec/features/github_registration_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 feature 'GithubAuthRegistration', type: :feature do
diff --git a/spec/features/registration_spec.rb b/spec/features/registration_spec.rb
index 220a050f..ff64ea01 100644
--- a/spec/features/registration_spec.rb
+++ b/spec/features/registration_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 feature 'Registration', type: :feature do
diff --git a/spec/features/submissions_spec.rb b/spec/features/submissions_spec.rb
index 1e443c3e..28063656 100644
--- a/spec/features/submissions_spec.rb
+++ b/spec/features/submissions_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 feature 'Submissions', type: :feature do
diff --git a/spec/features/teams_spec.rb b/spec/features/teams_spec.rb
index 4b86f259..ff4940f5 100644
--- a/spec/features/teams_spec.rb
+++ b/spec/features/teams_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 feature 'Teams', type: :feature do
diff --git a/spec/features/tests_spec.rb b/spec/features/tests_spec.rb
index d01ada5d..29fbe7df 100644
--- a/spec/features/tests_spec.rb
+++ b/spec/features/tests_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 feature 'Tests', type: :feature do
diff --git a/spec/fixtures/dummy_programs/adder_wrong_permissions b/spec/fixtures/dummy_programs/adder_wrong_permissions
old mode 100644
new mode 100755
diff --git a/spec/mailers/previews/devise_preview.rb b/spec/mailers/previews/devise_preview.rb
index 1437fbe5..fc99ff72 100644
--- a/spec/mailers/previews/devise_preview.rb
+++ b/spec/mailers/previews/devise_preview.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class DevisePreview < ActionMailer::Preview
   if User.devise_modules.include? :confirmable
     def confirmation_instructions
diff --git a/spec/models/ability_spec.rb b/spec/models/ability_spec.rb
index 39c96dfa..7bb396e8 100644
--- a/spec/models/ability_spec.rb
+++ b/spec/models/ability_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 describe Ability, type: :model do
diff --git a/spec/models/assignment_spec.rb b/spec/models/assignment_spec.rb
index 77e82009..fc09cdc2 100644
--- a/spec/models/assignment_spec.rb
+++ b/spec/models/assignment_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 describe Assignment, type: :model do
diff --git a/spec/models/author_contribution_test_spec.rb b/spec/models/author_contribution_test_spec.rb
index 947bdb55..e88fce00 100644
--- a/spec/models/author_contribution_test_spec.rb
+++ b/spec/models/author_contribution_test_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 describe AuthorContributionTest, type: :model do
diff --git a/spec/models/course_spec.rb b/spec/models/course_spec.rb
index d3adacde..b59cff38 100644
--- a/spec/models/course_spec.rb
+++ b/spec/models/course_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 describe Course, type: :model do
diff --git a/spec/models/expected_output_test_spec.rb b/spec/models/expected_output_test_spec.rb
index eafe812d..2b9814ea 100644
--- a/spec/models/expected_output_test_spec.rb
+++ b/spec/models/expected_output_test_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 describe ExpectedOutputTest, type: :model do
diff --git a/spec/models/file_submission_spec.rb b/spec/models/file_submission_spec.rb
index f1106e90..be9e6e9e 100644
--- a/spec/models/file_submission_spec.rb
+++ b/spec/models/file_submission_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 describe FileSubmission, type: :model do
diff --git a/spec/models/identity_spec.rb b/spec/models/identity_spec.rb
index 0ea396d2..5385b578 100644
--- a/spec/models/identity_spec.rb
+++ b/spec/models/identity_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 RSpec.describe Identity, type: :model do
diff --git a/spec/models/membership_spec.rb b/spec/models/membership_spec.rb
index 879de0db..99ec2986 100644
--- a/spec/models/membership_spec.rb
+++ b/spec/models/membership_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 describe Membership, type: :model do
diff --git a/spec/models/regexp_output_test_spec.rb b/spec/models/regexp_output_test_spec.rb
index cdb783cf..28f810ca 100644
--- a/spec/models/regexp_output_test_spec.rb
+++ b/spec/models/regexp_output_test_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 describe RegexpOutputTest, type: :model do
diff --git a/spec/models/required_file_test_spec.rb b/spec/models/required_file_test_spec.rb
index 43f2264e..38869ddb 100644
--- a/spec/models/required_file_test_spec.rb
+++ b/spec/models/required_file_test_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 describe RequiredFileTest, type: :model do
diff --git a/spec/models/submission_spec.rb b/spec/models/submission_spec.rb
index 57b0e766..a9ba8f03 100644
--- a/spec/models/submission_spec.rb
+++ b/spec/models/submission_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 describe Submission, type: :model do
diff --git a/spec/models/team_spec.rb b/spec/models/team_spec.rb
index 1e3c4614..4b53738e 100644
--- a/spec/models/team_spec.rb
+++ b/spec/models/team_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 describe Team, type: :model do
diff --git a/spec/models/test_spec.rb b/spec/models/test_spec.rb
index 2391f453..b6788dff 100644
--- a/spec/models/test_spec.rb
+++ b/spec/models/test_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 describe Test, type: :model do
diff --git a/spec/rails_helper.rb b/spec/rails_helper.rb
index 8842835c..cee42f72 100644
--- a/spec/rails_helper.rb
+++ b/spec/rails_helper.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # This file is copied to spec/ when you run 'rails generate rspec:install'
 ENV['RAILS_ENV'] ||= 'test'
 require File.expand_path('../../config/environment', __FILE__)
@@ -66,7 +67,7 @@
   config.include FactoryGirl::Syntax::Methods
 
   config.include Devise::Test::ControllerHelpers, type: :controller
-  [:controller, :view, :request].each do |type|
+  %i[controller view request].each do |type|
     config.include ::Rails::Controller::Testing::TestProcess, type: type
     config.include ::Rails::Controller::Testing::TemplateAssertions, type: type
     config.include ::Rails::Controller::Testing::Integration, type: type
diff --git a/spec/requests/setup_spec.rb b/spec/requests/setup_spec.rb
index c4d17fef..05e2b4cf 100644
--- a/spec/requests/setup_spec.rb
+++ b/spec/requests/setup_spec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'rails_helper'
 
 RSpec.describe 'Setup', type: :request do
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 9d3c6a0e..c2f210f0 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require 'devise'
 # This file was generated by the `rails generate rspec:install` command. Conventionally, all
 # specs live under a `spec` directory, which RSpec adds to the `$LOAD_PATH`.