Our own [`.gitlab-ci.yml`](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/.gitlab-ci.yml) is huge (1121 lines as of writing this). We have the [`include:local`](https://docs.gitlab.com/ee/ci/yaml/#includelocal) feature. Let's use it and split the config files into smaller pieces. We already do that [for Danger](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/Dangerfile).