4: File Uploads with Paperclip

Now that we've refactored to polymorphic behavior, we can finally add our PhotoShout. In order to upload photos, we'll be making use of the Paperclip gem. We'll use this gem in order to generate some thumbnails. In order to generate these thumbnails, you'll need to make sure to have imagemagick installed on your system. You can reference instructions here. We'll also make sure to add the necessary validations to prevent XSS attacks.