[Templating] added missing @return PHPDoc for LoaderInterface::isFresh method.

src/Symfony/Component/Templating/Loader/LoaderInterface.php

@@ -39,6 +39,8 @@ interface LoaderInterface
      * @param TemplateReferenceInterface $template A template
      * @param integer                    $time     The last modification time of the cached template (timestamp)
      *
+     * @return Boolean
+     *
      * @api
      */
     function isFresh(TemplateReferenceInterface $template, $time);