Changed fields attribute to use tuples instead of lists in rango/forms.py, deleted the context variable from the user_logout view as it was not used
Merge pull request #5 from canibanoglu/chapter8

Fixes for Chapter8 - some simple tidy ups.
In the two ModelForm Meta classes, changed the list of fields to a tuple of fields (where fields are strings).
Also removed the new RequestContext() command from the user logout view - it isn't used.