Verify that event fired on an order, in orders_controller, is an event and not any other method.

Steps to Reproduce

1. Create an order and complete it.
2. Sign in as admin.
3. Now use POSTMAN extension on chrome or send an curl request.
4. Now send url for fire action of orders_controller, and write any method of order lets say 'delete'.
5. Now send the request and the order gets deleted.