Rating::upgrade

static function upgrade()
{
	$limit = DailyLimit::instance()->getLimit();
	$limit = $limit ?: self::getInitialLimit();
	$limit = $limit * self::getLimitMultiplier();
	if ($limit > self::getMaxLimit())
	{
		return;
	}

	DailyLimit::instance()->setLimit($limit);

	Notification::create()
		->withMessage(self::getNotifyText('upgraded'))
		->toAllAuthors()
		->send();
}