ee/spec/services/milestones/update_service_spec.rb is failing on master

  7) Milestones::UpdateService#execute refresh related epic dates updates milestone sourced dates
     Failure/Error: create(:issue, milestone: milestone, epic: epic)

     ActiveRecord::RecordInvalid:
       Validation failed: Milestone {:message=>"is invalid"}
     # ./ee/spec/services/milestones/update_service_spec.rb:12:in `block (4 levels) in <top (required)>'