get_query_set incompatible with Django 1.8

[legrostdg]

The get_query_set method has been renamed to get_queryset in Django 1.6 https://docs.djangoproject.com/en/1.8/releases/1.6/#get-query-set-and-similar-methods-renamed-to-get-queryset and is removed in Django 1.8 https://docs.djangoproject.com/en/1.8/releases/1.8/#features-removed-in-1-8

Traceback:
File "/home/user/my-env/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  132.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/home/user/my-env/local/lib/python2.7/site-packages/knowledge/views.py" in knowledge_index
  45.     questions = Question.objects.can_view(request.user)\
File "/home/user/my-env/local/lib/python2.7/site-packages/knowledge/managers.py" in can_view
  10.         qs = super(QuestionManager, self).get_query_set()\

Exception Type: AttributeError at /knowledge/
Exception Value: 'super' object has no attribute 'get_query_set'