Implement build stage_id reference migration clean up

db/migrate/20170710083355_build_stage_id_ref_migration_cleanup.rb

+require Rails.root.join('db', 'post_migrate', '20170628080858_migrate_stage_id_reference_in_background')
+
+class BuildStageIdRefMigrationCleanup < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  ##
+  # `MigrateStageIdReferenceInBackground` background migration cleanup.
+  #
+  def up
+    Gitlab::BackgroundMigration
+      .steal(MigrateStageIdReferenceInBackground::MIGRATION)
+  end
+
+  def down
+    # noop
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170707184244) do
+ActiveRecord::Schema.define(version: 20170711145558) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"