Fixed #29966 -- Add test coverage for BaseHandler's "The view didn't return an HttpResponse object." error

[hramezani]

ticket_29966

It covers FBV:

django/django/core/handlers/base.py

Line 119 in d5f4ce9

if isinstance(callback, types.FunctionType): # FBV

But I don't know how to test the CBV. I test some class-based view like this:

class WithoutReponse(ListView):

    def get(self, request):
        pass

But, when I call this view, the callback type is FunctionType and the else block doesn't execute.

[hramezani]

@timgraham ClassBasedView test added based on your comment on ticket. Thank you.