Backport push mirroring to CE
One of the most popular requests of GitLab is to make mirroring a CE feature (https://gitlab.com/gitlab-org/gitlab-ce/issues/18732)
Push mirroring particularly would be useful fo help people move to GitLab CE from other Git servers, by allowing them to enjoy the benefits of GitLab and push mirror their projects to other places like GitHub. Building features that help individuals and organizations of all sizes move to GitLab is a good thing.
- Backport push mirroring to GitLab CE from GitLab EES