[Issue 9] Tests now recognized in admin

The admins of the site are now able to view, create, edit, and delete tests. The test model will perform error checking on the total list of words and the list of words spelled correctly.

 TODO: Change the default widget being used by the correct/total word lists. Something that will just list the word and provide a button to add a new word to the list would be better than the small select box which shows a couple word at a time and requires the admin to scroll.