Merge remote-tracking branch 'dev/master' into 'master'

app/controllers/admin/application_controller.rb

app/controllers/admin/impersonation_controller.rb

app/controllers/admin/impersonations_controller.rb

app/controllers/admin/users_controller.rb

app/finders/snippets_finder.rb

app/helpers/issues_helper.rb

app/models/project_services/buildkite_service.rb

app/models/project_services/issue_tracker_service.rb

app/models/project_services/jira_service.rb

app/models/project_services/slack_service.rb

app/services/merge_requests/build_service.rb

app/services/notes/create_service.rb

app/views/layouts/header/_default.html.haml

config/routes.rb

lib/api/milestones.rb

lib/api/project_snippets.rb

spec/controllers/admin/impersonation_controller_spec.rb

spec/controllers/admin/impersonations_controller_spec.rb

spec/controllers/admin/users_controller_spec.rb

spec/features/merge_requests/create_new_mr_spec.rb