Call #upload_path from inside BaseAttachmentsController#clean?
Call #upload_path from inside BaseAttachmentsController#clean?

Also memoize BaseAttachmentsController#upload_path so it can be called
multiple times within a request without having to be computed each time.

I think this makes the code easier to understand.

alphagov/whitehall,alphagov/whitehall,alphagov/whitehall,alphagov/whitehall