Create Three Symfony Back Ends - Part #12 - Update with PUT

Next up is PUT. This is where we start taking data that exists in our system, and making modifications to it. There's two ways we will do this, one is a touch contentious. To update we use either PUT, or PATCH. With PUT we are expected to send in a full resource, and our implementation will apply our changes over the top of the existing entity. With PATCH we can send in only the fields that change, and any existing properties will be left alone.