Added model specs

[keshavbiswa]

Pull Request Template

Description

• Noticed missing model specs
• Added missing model specs
• Added rubocop rspec cops

Please include a summary of the change and which issue is fixed. Please also
include relevant motivation and context. List any dependencies that are required
for this change.

Fixes # (issue)

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to
  not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Checklist:

• I have manually tested all workflows
• I have performed a self-review of my own code
• I have added automated tests for my code

[github-actions]

Current Code Coverage Percent of this PR:

58.79 %

Files having coverage below 100%

Impacted Files	Coverage
/app/controllers/companies_controller.rb	92.86 %
/app/helpers/application_helper.rb	93.33 %
/app/helpers/team_helper.rb	57.14 %
/app/controllers/projects_controller.rb	50.0 %
/app/controllers/time_tracking_controller.rb	30.0 %
/app/controllers/concerns/timesheet.rb	37.5 %
/app/controllers/root_controller.rb	33.33 %
/app/controllers/team_controller.rb	38.46 %
/app/controllers/dashboard_controller.rb	66.67 %
/app/controllers/clients_controller.rb	66.67 %
/app/controllers/concerns/error_handler.rb	60.0 %
/app/models/timesheet_entry.rb	88.24 %
/app/models/project.rb	90.91 %
/app/controllers/companies/purge_logo_controller.rb	50.0 %
/app/controllers/users/passwords_controller.rb	41.67 %
/app/controllers/users/omniauth_callbacks_controller.rb	25.0 %
/app/controllers/users/sessions_controller.rb	25.0 %
/app/controllers/users/registrations_controller.rb	45.83 %
/app/controllers/users/invitations_controller.rb	63.64 %
/app/controllers/internal_api/v1/application_controller.rb	85.71 %
/app/controllers/internal_api/v1/timesheet_entry_controller.rb	35.71 %
/lib/authentication/google.rb	0.0 %

[akhilgkrishnan]

LGTM 🎉

[rohitjoshixyz]

Approved with changes requested for a spec @keshavbiswa