Better errors when serializer has incorrectly named field.

[picturedots]

If I have a mistake in my model serializer where there's a serializer field name that isn't mapped to a field in the model, e.g.

class MySerializer(serializers.ModelSerializer):
    bad_serializer_field_name = MyCustomSerializer()

then the serializer fails silently and by returning no no data. It would be nice for debugging if the serialization process would issue a warning.