* master: (242 commits)
  Validate user namespace before saving so that errors persist on model
  Reset Project's column information in spec/lib/gitlab/background_migration/populate_merge_request_metrics_with_events_data_spec.rb
  Explicitly set cwd in Sidekiq memory killer instead of depending on getcwd
  Downgrade google-protobuf
  Close low level rugged repository in project cache worker
  File upload UI obeys LFS filters
  Resolve "Add a link to documentation on how to get external ip in the Kubernetes cluster details page"
  Upgrade GitLab Workhorse to v3.6.0
  Add sorting options for /users API (admin only)
  improvements from feedback
  [ci-skip] add changelog
  remove file after `Upload#destroy`
  Fix a hardcoded pipeline ID in a spinach step
  Override group sidebar links
  Replace "cluster" with "Kubernetes cluster"
  Reorder async/sync tasks in BuildFinishedWorker to read traces efficiently
  Fix tests for Drop filename enforcement
  Revert using expand_fixture_path in factory
  Revert "Add FixtureHelpers for FactoryGirl"
  Refactor :trace to :trace_live in spec
  ...