Remove Rails 4 compatibility
Supposing we will release 11.6 with rails 5 (https://gitlab.com/gitlab-org/gitlab-ce/issues/48991), there is no reason to keep rails 4 compatibility anymore.
There can be multiple separate MRs to achieve this:
- remove rails 4 jobs from
.gitlab-ci.yaml
andGemfile
- then follow up with MRs which remove
if not Gitlab.rails5
from code