Claim Assosciated pdf

I can see why you've inherited from `AttachmentUploader`, but it doesn't really make sense. We should pull out `store_dir`, into an abstract superclass or even hoist it up into `CarrierWave::Uploader::Base` in an initialiser. Also `storage :file` needs to come out of `AttachmentUploader` and into the carrier wave initialiser for the non-production cases.