showing representatives alphabetically grouped and able to add and change twitter id
added index and show files
added error message. Closes #381
small change to update_attributes
added tests and corrected class inheritance
Merge branch 'representatives-admin' of git://github.com/katfa/hdo-site into katfa-representatives-admin
Add email attr to representative + improve editing of twitter/email.

Also remove the representative#index variants, which are very rarely visited.