send audio message

        :param url: link to the audio file
        :param user: target user
        :param options:
        :return:

async def send_audio(self, url, user, options=None):
        """
        send audio message

        :param url: link to the audio file
        :param user: target user
        :param options:
        :return:
        """
        tasks = [interface.send_audio(user, url, options) for _, interface in self.interfaces.items()]
        return [body for body in await asyncio.gather(*tasks)]