Fix issue with room posting

chat/serializers.py

@@ -10,7 +10,7 @@ class AppSerializer(serializers.HyperlinkedModelSerializer):
 class RoomSerializer(serializers.HyperlinkedModelSerializer):
     class Meta:
         model = Room
-        fields = ['id', 'name']
+        fields = ['id', 'name', 'app']
 
 class MessageSerializer(serializers.HyperlinkedModelSerializer):
     class Meta: