(revised) Add new vote function for AJAXification

I'm following along with this tutorial by Arun Ravindran to make the
vote function AJAX: https://www.youtube.com/watch?v=QEktHo5-kBY&hd=1

I deleted the following from models.py because it was making my new
form-based vote function say my form is invalid.

class Meta:
unique_together = ('voter', 'quote',)

I was thinking it should be okay to remove "unique_together" because the
user won't have a function that will let users vote multiple times on
the same quote...but if unique_together is a must have, please lemme
know.