Fixed assumption of dict ordering

testproj/articles/views.py

@@ -49,7 +49,7 @@ class ArticleViewSet(viewsets.ModelViewSet):
     pagination_class = ArticlePagination
     filter_backends = (DjangoFilterBackend, OrderingFilter)
     filter_fields = ('title',)
-    ordering_fields = ('date_modified','date_created')
+    ordering_fields = ('date_modified', 'date_created')
     ordering = ('date_created',)
 
     @swagger_auto_schema(auto_schema=NoPagingAutoSchema)

testproj/users/serializers.py

@@ -1,7 +1,6 @@
 from django.contrib.auth.models import User
 from rest_framework import serializers
 
-from articles.models import Article
 from snippets.models import Snippet