Support views with no model #56
Description
Worf currently raises ImproperlyConfigured if model is set to the default value of None, but None should probably be supported.
django.core.exceptions.ImproperlyConfigured: Model is not set on ...
If you set model to something else like False it then falls down when trying to build the filterset:
AttributeError: 'bool' object has no attribute '__name__'
Supplying your own queryset via get_queryset or response via get both bypass the need for a model which is handy in certain cases, currently the only way to suppress the error is to pass a model e.g. the django.db.models.Model abstract, even though it isn't used for anything meaningful.