Removed admin registration
Changed Admins to Users in preparation for implementing CanCan.
Implemented PaperClip for handling data uploads. Haven't implemented
the business logic for parsing the data file contents yet.
Working for gem set for mocha & shoulda with redgreen output.
When uploading data files, it parses the contents and creates sales
records from it.

* TODO: for some reason, the paperclip attachment is now being saved as a blank file...
* Need to re-work the Sales section to load Sales Records from a machine (and the machines section too)