Merge commit '46e4ed6b' into feature/multi-level-container-registry-images

* commit '46e4ed6b': (28 commits)
  Award emoji button smiley animation
  Introduced empty/error UX states to environments monitoring.
  Github import rake task
  Remove individual modal width styles
  Fix RuboCop for removing index
  Link to docs site for file in doc/
  Disable invalid service templates (again)
  Show CI status as Favicon on Pipelines, Job and MR pages
  STL file viewer
  Wait for the PDF to be loaded before doing anything
  remove unnecessary lease as cron job
  Search for opened MRs - include reopened  MRs
  ProjectsFinder should handle more options
  Clearly show who triggered the pipeline in email
  Make it possible to preview pipeline success/failed emails
  Add remove_concurrent_index to database helper
  Add more tests for subgroups feature
  Large features by the 1st, small ones by the 3rd
  Ask people to create EE MRs on the 7th
  fix project authorizations migration issue
  ...