Publish thing state to AWS IoT.

        Args:
            state (dict): object state. Must be JSON serializable (i.e., not
                have circular references).

def publish_state(self, state):
        """Publish thing state to AWS IoT.

        Args:
            state (dict): object state. Must be JSON serializable (i.e., not
                have circular references).
        """
        message = json.dumps({'state': {'reported': state}})
        self.client.publish(self.topic, message)
        self._state = state