User groups (that can be assigned as approvers)
Zendesk issue: https://gitlab.zendesk.com/agent/tickets/13653
Somewhat related to #179 (closed), the customer has different groups of people that are responsible for a release branch. It would be nice to be able to reference a user group in the approver's list instead of having to type out each name separately. The approvers changes for each release so it's updated often.
This is also somewhat related to the discussion in gitlab-org/gitlab-ce#2772 where we discuss whether teams are a good fit again.