Fix typo

tests/test_app/TestApp/Mailer/TestMailer.php

@@ -11,7 +11,7 @@
  *
  * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
  * @link          http://book.cakephp.org/2.0/en/development/testing.html CakePHP(tm) Tests
- * @since         1.3.0
+ * @since         3.1.0
  * @license       http://www.opensource.org/licenses/mit-license.php MIT License
  */
 namespace TestApp\Mailer;