Turn off receiver via HTTP get command.

def power_on(self):
        """Turn off receiver via HTTP get command."""
        try:
            if self.send_get_command(self._urls.command_power_on):
                self._power = POWER_ON
                self._state = STATE_ON
                return True
            else:
                return False
        except requests.exceptions.RequestException:
            _LOGGER.error("Connection error: power on command not sent.")
            return False