Rename Media to Attachment
Add Carrierwave and MiniMagick to Gemfile
Create ImageUploader and mount it to Attachment
Add Carrierwave to Rakefile and bin/console
Add attachments controller
Return status in Attachments Controller
Fix association name
Move ImageUploader in uploaders dir
Add type column to attachments
Add picture, audio and video attachments
Merge remote-tracking branch 'origin/attachments'