Add support for cursor based pagination

[erichaus]

After lots of head scratching we just determined that our test was failing because it has cursor pagination enabled, does this package support it or what would be needed to make it work?

class FooViewSet(viewsets.ModelViewSet):
    serializer_class = serializers.FooSerializer
    pagination_class = FooCursorPagination

    def get_queryset(self):
        qs = models.Foo.objects.all()
        return qs

[sliverc]

Marking as help wanted if someone wants to pick up the PR. As a side node renderer_context won't fail anymore when it is None - this has been fixed with #396