Added username and password to Auctioneer

Initially auctioneer had no unique attributes to distinguish one from the other. By adding these
two columns into the model, the auctioneers will now have a distinct different amoungst them.

Ran db:migrate and then the test suite to ensure changes were implement properly.
Merge pull request #6 from Onaracs/fix/auctioneer_add_email_password

Added username and password to Auctioneer