Heroku uploads broken --> add S3 option?

[orenyk]

Currently, if you deploy to Heroku and try to upload any files (equipment images, equipment documentation, favicon, etc) using paperclip, the files will be deleted shortly thereafter since they are stored locally and Heroku spins up new VMs for the app as needed. We should offer a configurable option to store files on S3 and remove any hard dependencies on local storage. (inspired by #1016 and #1181)

[squidgetx]

These will probably help:

https://devcenter.heroku.com/articles/paperclip-s3

https://github.com/thoughtbot/paperclip/wiki/Paperclip-with-Amazon-S3

Basically we just need to define some more config in production.rb