Add a new Danger check to add a failure if the branch is too far behind the canonical master
Following https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/19066, we should add a check that fails the pipeline if the source branch is too far behind (200, 300, 400, 500 commits?) the canonical master
.
This would be an improvement towards the "Rebase hygiene" effort.
/cc @meks