Merge branch 'pipeline-emails' into pipeline-notifications

* pipeline-emails: (58 commits)
  Update endpoint to username validator
  change border color to variable
  Add todo for deprecated user routes and more information about deprecation to changelog
  Provide better error message to the user
  Apply better hierarchy to markdown headers and issue/mr titles
  Swapped button text manipulation outcomes for the toggle query
  Fixed find file keyboard navigation
  Update CHANGELOG for 8.12.7
  Added download-button class and applied button margin
  Enable activerecord_sane_schema_dumper for test
  Updated logo from @luke
  Fix broken specs on MySQL after https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6896
  Fix Test Env (proper error handling when gitlab-shell is not clonned)
  Fix randomly crashing spinach test for merge request
  [Great spinach fix] Replace gsub with delete
  Remove carriage returns from commit description as summary is on a newline and will always include carriage returns
  Convert due_date_select.js filetype to es6.
  Stop directly parsing due_date with Date.parse, prefer parsing implicitly.
  Improve spec for pipeline metrics worker
  Add Pipeline metrics worker
  ...