Merge remote-tracking branch 'upstream/master' into ce-to-ee-2017-09-20

# Conflicts:
#	LICENSE
#	app/controllers/projects/refs_controller.rb
#	spec/javascripts/vue_mr_widget/stores/mr_widget_store_spec.js
#	spec/lib/gitlab/ci/yaml_processor_spec.rb
#	spec/policies/project_policy_spec.rb
#	spec/requests/api/boards_spec.rb
#	spec/requests/api/v3/builds_spec.rb
[ci skip]