Add GitLab CI and sort Gemfile

The provision folder contains files required to build the Docker Image for the GitLab CI.

provision/provision.docker.user.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+USER=codeocean
+ruby_version="2.7.2"
+rails_version="5.2.4.4"
+
+cd ~
+
+# RVM
+gpg --keyserver hkp://pool.sks-keyservers.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB
+curl -sSL https://rvm.io/mpapis.asc | gpg --import -
+curl -sSL https://rvm.io/pkuczynski.asc | gpg --import -
+curl -sSL https://get.rvm.io | bash -s stable
+
+echo 'source /home/codeocean/.rvm/scripts/rvm' >> /home/${USER}/.profile
+
+source /home/codeocean/.rvm/scripts/rvm
+rvm autolibs disable
+rvm requirements
+rvm install "${ruby_version}"
+rvm use "${ruby_version}" --default
+
+# rails
+gem install rails -v "${rails_version}"
+gem install bundler
+bundle install --gemfile=/tmp/Gemfile