Gitlab docker-compose files

Setup

1. Make necessary configurations in gitlab.rb
2. docker-compose up -d gitlab
3. docker cp gitlab.rb <container name>:/etc/gitlab/gitlab.rb
4. docker-compose up -d --force-recreate

Register the runner

Maintenance

1. Go to the Gitlab docker-compose folder
2. git pull
3. docker-compose pull
4. docker-compose up -d