[Backport] Support multiple assignees for merge requests (!27089) · Merge requests · GitLab.org / GitLab FOSS · GitLab

Oswaldo Ferreira requested to merge osw-multi-assignees-merge-requests into master Apr 07, 2019

What does this MR do?

This backports EE https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/10161 but not necessarily ports the feature to CE.