Require build to succeed prior to merge
It is possible to merge even when a CI build fails. This can introduce errors. We had such a situation on the www-gitlab-com repo; see internal slack conversation: https://gitlab.slack.com/archives/builds/p1461342188000077
It seems that it should be possible to disallow a merge if the build fails; this can be a branch level setting perhaps?
\cc @stanhu @ayufan @rspeicher