Renders the resource payload.
        :returns: a dict representing the object to be used as payload for a request

def payload(self):
        """
        Renders the resource payload.
        :returns: a dict representing the object to be used as payload for a request
        """
        payload = {'type': self.resource_type(), 'attributes': self.attributes}
        if self.id:
            payload['id'] = self.id
        return payload