Check if connection is alive every reconnect_timeout seconds.

def _check_connection(self):
        """Check if connection is alive every reconnect_timeout seconds."""
        if ((self.tcp_disconnect_timer + 2 * self.reconnect_timeout) <
                time.time()):
            self.tcp_disconnect_timer = time.time()
            raise OSError('No response from {}. Disconnecting'.format(
                self.server_address))
        if (self.tcp_check_timer + self.reconnect_timeout) >= time.time():
            return
        msg = Message().modify(
            child_id=255, type=self.const.MessageType.internal,
            sub_type=self.const.Internal.I_VERSION)
        self.add_job(msg.encode)
        self.tcp_check_timer = time.time()