Document usage and alter script accordingly

Author: gregcorbett

tests/manualTests/TestRoleRequestEmail.php

@@ -2,8 +2,8 @@
 
 # This is designed to sanity check the role request email functionality.
 # It is not a unit test, it is designed to be run against the sample data.
-
-require_once __DIR__.'/lib/Gocdb_Services/NotificationService.php';
+# Usage: php tests/manualTests/TestRoleRequestEmail.php
+require_once 'lib/Gocdb_Services/NotificationService.php';
 
 $requesting_user_id = 5; // This corresponds to Richard Winters.
 $requesting_user = \Factory::getUserService()->getUser($requesting_user_id);