Merge remote-tracking branch 'upstream/master' into pipeline-emails

* upstream/master: (206 commits)
  Implement fourth round of comments from @DouweM.
  Fix `CreateDeploymentService` spec.
  Reload issues in spec to ensure label<->issue mapping properly loaded
  Fix build.
  Remove unnecessary #{} in cycle analytics template.
  Update cycle analytics icon and fix color of the dismiss button.
  Use triple dashes for the empty value in cycle analytics.
  Fix typo on cycle analytics copy.
  Add page title and fix sub menu width in Cycle Analytics page.
  Update Cycle Analytics Read more link URL.
  Display the cycle analytics navbar based on the `:read_cycle_analytics` ability.
  Improve indentation in `Gitlab::Database::Median`
  Add a spec for merge request metric caching while refreshing a merge request from a forked project.
  Use the `IssuableBaseService` lifecycle hooks to cache `MergeRequestsClosingIssues`
  Implement a second round of review comments from @DouweM.
  Add docs on Cycle Analytics
  Test if issue authors can access private projects
  Update .pkgr.yml with Ubuntu 16.04 dependencies
  fix issues mr counter
  Move JSON generation (cycle analytics) into a controller method.
  ...