title: Django rest framework override page_size in ViewSet
body: <p>I am having problem with django rest framework pagination.
  I have set pagination in settings like -</p>
  
  <pre><code>'DEFAULT_PAGINATION_CLASS':'rest_framework.pagination.PageNumberPagination',
  'PAGE_SIZE': 1
  </code></pre>
  
  <p>Below is my viewset. </p>
  
  <pre><code>class HobbyCategoryViewSet(viewsets.ModelViewSet):    
      serializer_class = HobbyCategorySerializer
      queryset = UserHobbyCategory.objects.all()
  </code></pre>
  
  <p>I want to set different page size for this viewset. I have tried setting page_size and Paginate_by class variables but list is paginated according to PAGE_SIZE defined in settings. Any idea where I am wrong ?</p>