Updated PaymentMethod._attach_objects_hook to handle nested Customer Object
Updated PaymentMethod._attach_objects_hook to handle nested Customer Object

Earlier PaymentMethod was assuming that customer_id was present as "cus_6lsBvm5rJ0zyHc" but in case expand_fields is used to expand the customer object it would be present as {"id": "cus_6lsBvm5rJ0zyHc"}

pydanny/dj-stripe,pydanny/dj-stripe,dj-stripe/dj-stripe,dj-stripe/dj-stripe