N°2651 rollback gitignore for lib tests dirs

Too dangerous ! We'll work properly on this but for 2.8

lib/symfony/framework-bundle/Tests/DependencyInjection/Fixtures/TestBundle/TestBundle.php

@@ -0,0 +1,18 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Bundle\FrameworkBundle\Tests;
+
+use Symfony\Component\HttpKernel\Bundle\Bundle;
+
+class TestBundle extends Bundle
+{
+}