compatible with Django 1.6

[overratedpro]

File "............/lib/python2.7/site-packages/pennyblack/models/newsletter.py", line 4, in
from django.conf.urls.defaults import patterns, url
ImportError: No module named defaults

the line
from django.conf.urls.defaults import patterns, url
is already deprecated in Django 1.5, instead should be:
from django.conf.urls import patterns, url

[Marc Egli]

feel free to open a pull request