Adds stuck mirror cleanup post migration

db/post_migrate/20170808150315_fail_stuck_mirrors.rb

+class FailStuckMirrors < ActiveRecord::Migration
+  DOWNTIME = false
+
+  def up
+    stuck_mirrors_query = "import_jid IS NULL AND ((import_status = 'started' AND project_mirror_data.last_update_started_at < :limit) OR (import_status = 'scheduled' AND project_mirror_data.last_update_scheduled_at < :limit))"
+
+    Project.mirror.joins(:mirror_data).where(
+      "import_jid IS NULL AND ((import_status = 'started' AND project_mirror_data.last_update_started_at < :limit) OR (import_status = 'scheduled' AND project_mirror_data.last_update_scheduled_at < :limit))",
+      { limit: 20.minutes.ago  }
+    )
+  end
+
+  def down
+  end
+end