The procps project for a few years has been hosted at Gitorious. With the announcement that Gitorious has been acquired by GitLab and that all repositories need to move there, procps moved along to GitLab. At first I thought it would just be a like for like thing, but then I noticed that GitLab has this GitLab CI feature and had to try it out.
CI here stands for Continuous Integration and is a way of automatically testing your program builds using a bunch of test scripts. procps already has a set of tests, with some a level of coverage that has room for improvement, so it was a good candidate to use for CI. The way GitLab works is they have a central control point that is linked to the git repo and you create runners, which are the systems that actually compile the programs and run the tests. The runners then feed back their results and GitLab CI shows it all in pretty red or green.