Add aws-sdk so we can use S3 as the new storage for paperclip attachments
Separate form and process for uploading city banners to S3
Add progress bar to city banner upload
Add DelayedJob gem and build service to process and upload to S3
Hook up admin city create action to new CitySaveService. Delay processing of S3 uploaded file
Process S3 uploads in the background
Add logging to S3UploadedFileProcessorService
Handle case where a new banner is uploaded before the last one was processed.