Implement {upload,receive}-pack RPCs
Closes #122 (closed) Associated with https://gitlab.com/gitlab-org/gitlab-workhorse/merge_requests/143
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Closes #122 (closed) Associated with https://gitlab.com/gitlab-org/gitlab-workhorse/merge_requests/143