Merge branch 'qa-quarantine-add-member-test' into 'master'

Quarantine failing test

See merge request gitlab-org/gitlab-ce!26028

qa/qa/specs/features/browser_ui/1_manage/project/add_project_member_spec.rb

 # frozen_string_literal: true
 
 module QA
-  context 'Manage' do
+  # Failure issue: https://gitlab.com/gitlab-org/quality/staging/issues/45
+  context 'Manage', :quarantine do
     describe 'Add project member' do
       it 'user adds project member' do
         Runtime::Browser.visit(:gitlab, Page::Main::Login)