repair adding messages

JoinTheCityREST/app/Discussion/views.py

@@ -16,7 +16,7 @@ class DiscussionViewSet(viewsets.ModelViewSet):
     serializer_class = DiscussionSerializer
     permission_classes = (permissions.IsAuthenticatedOrReadOnly,)
 
-    @detail_route()
+    @detail_route(methods=['post'])
     def add(self, request, pk=None):
         discussion = get_object_or_404(self.queryset, pk=pk)
         text = request.data.get('text')