* master: (51 commits)
  Move locked check to a guard-clause
  Ci::Build tag is a trait instead of an own factory
  [CE backport] Saved configuration for issue board
  Use the correct project visibility in system hooks
  Add changelog
  more readable changelog
  Make merge_jid handling less stateful in MergeService
  Fetch the merged branches at once
  remove extra whitespace
  use a delegate for `username` to be more future friendly
  Merging EE doc into CE
  add changelog entry
  Avoid using Rugged in Gitlab::Git::Wiki#preview_slug
  Cache commits on the repository model
  Remove groups_select from global namespace & simplifies the code
  Change default disabled merge request widget message to "Merge is not allowed yet"
  Semi-linear history merge is now available in CE.
  Remove repetitive karma spec
  Improve spec to check hidden component
  Rename to shouldShowUsername
  ...