-class AddContainerLockCount < ActiveRecord::Migration
+# Copyright (C) The Arvados Authors. All rights reserved.
+#
+# SPDX-License-Identifier: AGPL-3.0
+
+class AddContainerLockCount < ActiveRecord::Migration[4.2]
def change
add_column :containers, :lock_count, :int, :null => false, :default => 0
end