Authenticate to start listening to user events.

def listen_user_events(self):
        """
        Authenticate to start listening to user events.
        """

        if not self._user_id:
            raise AmigoCloudError(self.error_msg['logged_in_websockets'])

        response = self.get('/me/start_websocket_session')
        websocket_session = response['websocket_session']
        auth_data = {'userid': self._user_id,
                     'websocket_session': websocket_session}
        self.amigosocket.emit('authenticate', auth_data)