.gitlab-ci.yml documentation out-of-date
If you google for ".gitlab-ci.yml", the first result is to http://doc.gitlab.com/ci/yaml/README.html.
This file is out-of-date, as it is generated from gitlab-org/gitlab-ci, which is obsolete, now that CI is integrated into GitLab 8.0.
For example, it doesn't have information about the new artifacts
key, which is documented at the 8.2 release blog post.