Update README.md

Fixing path. If the file is in `test`, you just need to go up *one* level.

Author: ThomasLandauer

README.md

@@ -71,7 +71,7 @@ For example, in a Symfony project, `object-manager.php` would look something lik
 ```php
 <?php
 
-require dirname(__DIR__).'/../config/bootstrap.php';
+require __DIR__.'/../config/bootstrap.php';
 $kernel = new \App\Kernel($_SERVER['APP_ENV'], (bool) $_SERVER['APP_DEBUG']);
 $kernel->boot();
 return $kernel->getContainer()->get('doctrine')->getManager();