"on the fly" edits of images without uploading

Idea: you post your image to the API like `pictshare.com/api/transit/800x600/inverted?url=https://s3-server/image.jpg` and it serves you back the edited image. Could also work directly with uploads.

This way pictshare could be used as a "normalizer" eg when your website allows users to upload pictures but you want them in a specific format