[ticket/11413] Fix notification tests

Send types/methods the cache service, not the driver (not sure why the
driver was sent before)

PHPBB3-11413

phpBB/includes/notification/exception.php

@@ -0,0 +1,29 @@
+<?php
+/**
+*
+* @package notifications
+* @copyright (c) 2013 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License v2
+*
+*/
+
+/**
+* @ignore
+*/
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+/**
+* Notifications exception
+*
+* @package notifications
+*/
+class phpbb_notification_exception extends \Exception
+{
+	public function __toString()
+	{
+		return $this->getMessage();
+	}
+}