Restrict pushes / merges to a protected branch to specific people

Parent: gitlab-org/gitlab-ee#179

Proposal

• According to current / planned features in CE, here's the list of possible restrictions for pushing/merging to a protected branch:

  • Masters can push
  • Developers can push
  • No one can push
  • Masters can merge
  • Developers can merge

• To this list, this issue proposes adding the ability to add restrictions based on one or more specific users:

  • "User A, B & C" can push (and no one else, regardless of Master status)
  • "User A, B & C" can merge (and no one else, regardless of Master status)

Implementation Details

• the person / people should be added to the project with master level access
• this should be communicated in the UI