diff --git a/.circleci/config.yml b/.circleci/config.yml
index dd020b9e1..1d2c7d8cd 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -3,7 +3,7 @@ version: 2.1
 jobs:
   build-gcc-4_7-shared-serial-external: &build-template
     docker:
-      - image: nicolasbock/bml-ci-build:1.0
+      - image: nicolasbock/bml-ci-build:1
     environment:
       OMP_NUM_THREADS: 4
       CMAKE_BUILD_TYPE: Debug
@@ -230,7 +230,7 @@ jobs:
 
   lint:
     docker:
-      - image: nicolasbock/bml-ci-lint:1.0
+      - image: nicolasbock/bml-ci-lint:1
     steps:
       - checkout
       - run: bundle install
@@ -239,7 +239,7 @@ jobs:
 
   docs:
     docker:
-      - image: nicolasbock/bml-ci-docs:1.0
+      - image: nicolasbock/bml-ci-docs:1
     steps:
       - checkout
       - run: ./build.sh docs
diff --git a/Gemfile b/Gemfile
index 7c1a6885e..feb4b93f4 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 source "https://rubygems.org"
 
-gem "danger"
+gem "danger", "<8"
 gem "danger-commit_lint"
 gem "danger-mention"
 gem "danger-prose"
diff --git a/ci-images/build/Dockerfile b/ci-images/build/Dockerfile
index f2e068d06..12f11d161 100644
--- a/ci-images/build/Dockerfile
+++ b/ci-images/build/Dockerfile
@@ -1,6 +1,6 @@
 FROM ubuntu:xenial
 RUN apt-get update
-RUN apt-get install --assume-yes --no-install-recommends ca-certificates wget
+RUN apt-get install --assume-yes --no-install-recommends apt-transport-https ca-certificates wget
 COPY clang.list /etc/apt/sources.list.d
 COPY cmake.list /etc/apt/sources.list.d
 COPY toolchain.list /etc/apt/sources.list.d
@@ -8,6 +8,9 @@ RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 60C317803A41BA51845
 RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys DBA92F17B25AD78F9F2D9F713DEC686D130FF5E4
 RUN wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | apt-key add -
 RUN apt-get update
+RUN ln -fs /usr/share/zoneinfo/UTC /etc/localtime
+RUN apt-get install --assume-yes tzdata
+RUN DEBIAN_FRONTEND=noninteractive dpkg-reconfigure --frontend noninteractive tzdata
 RUN apt-get install --assume-yes --no-install-recommends apt-utils
 RUN apt-get install --assume-yes --no-install-recommends build-essential
 RUN apt-get install --assume-yes --no-install-recommends git-core openssh-client ca-certificates
diff --git a/ci-images/docs/Dockerfile b/ci-images/docs/Dockerfile
index b6e342d2f..268fb236f 100644
--- a/ci-images/docs/Dockerfile
+++ b/ci-images/docs/Dockerfile
@@ -1,6 +1,10 @@
 FROM ubuntu:focal
 RUN apt-get update
+RUN ln -fs /usr/share/zoneinfo/UTC /etc/localtime
+RUN apt-get install --assume-yes tzdata
+RUN DEBIAN_FRONTEND=noninteractive dpkg-reconfigure --frontend noninteractive tzdata
 RUN apt-get install --assume-yes --no-install-recommends apt-utils
+RUN apt-get install --assume-yes --no-install-recommends ca-certificates
 RUN apt-get install --assume-yes --no-install-recommends build-essential
 RUN apt-get install --assume-yes --no-install-recommends git-core openssh-client
 RUN apt-get install --assume-yes --no-install-recommends cmake cmake-data libblas-dev liblapack-dev
diff --git a/ci-images/lint/Dockerfile b/ci-images/lint/Dockerfile
index 775422887..a1a40567f 100644
--- a/ci-images/lint/Dockerfile
+++ b/ci-images/lint/Dockerfile
@@ -2,7 +2,11 @@ FROM ubuntu:xenial
 COPY emacs.list /etc/apt/sources.list.d
 RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 873503A090750CDAEB0754D93FF0E01EEAAFC9CD
 RUN apt-get update
+RUN ln -fs /usr/share/zoneinfo/UTC /etc/localtime
+RUN apt-get install --assume-yes tzdata
+RUN DEBIAN_FRONTEND=noninteractive dpkg-reconfigure --frontend noninteractive tzdata
 RUN apt-get install --assume-yes --no-install-recommends apt-utils
+RUN apt-get install --assume-yes --no-install-recommends ca-certificates
 RUN apt-get install --assume-yes --no-install-recommends git-core openssh-client
 RUN apt-get install --assume-yes --no-install-recommends bundler
 RUN apt-get install --assume-yes --no-install-recommends emacs26
diff --git a/refresh-ci-images.sh b/refresh-ci-images.sh
index d3e080b21..85e5c8892 100755
--- a/refresh-ci-images.sh
+++ b/refresh-ci-images.sh
@@ -3,7 +3,7 @@
 set -x
 
 : ${IMAGE_TAG:=bml-ci}
-: ${IMAGE_VERSION:=1.0}
+: ${IMAGE_VERSION:=1}
 
 for workflow in build lint docs; do
   docker build --tag nicolasbock/${IMAGE_TAG}-${workflow}:${IMAGE_VERSION} ci-images/${workflow}