Fix serializer mapping on some viewsets

api/v1/views.py

@@ -106,7 +106,7 @@ class ImageViewSet(ExtendedModelViewSet):
         'course', 'lesson', 'img',
     ).all()
     serializer_class = ImageCreateSerializer
-    serializer_class = {
+    serializer_class_map = {
         'list': ImageSerializer,
         'retrieve': ImageSerializer,
     }
@@ -140,7 +140,7 @@ class ImageTextViewSet(ExtendedModelViewSet):
         'course', 'lesson', 'img'
     ).all()
     serializer_class = ImageTextCreateSerializer
-    serializer_class = {
+    serializer_class_map = {
         'list': ImageTextSerializer,
         'retrieve': ImageTextSerializer,
     }