Update gems. Remove mongoid.
Regenerate assets. Close #221
Fix Travis-CI setting.
Fix Image class to use Paperclip properly.
Add images table.
Fix Travis-CI setting.
Fix Travis-CI setting.
Fix date time picker.
Fix dropdown of Bootstrap.
Fix Travis-CI setting.
Restore wrongly removed assets.
Merge pull request #225 from AI-comp/paperclip_221

Paperclip 221