On page 14 you say to add:
url(r'^$', views.index, name='home'),
Then on page 15 you say:
'collection.views.index' means that we’ll use the index view in views.py in our app collection, which we’ll do next.
We use views.index and it works, but you are referencing ‘collection.views.index’. Not sure if this is intentional but it is really confusing.