Skip PDOSessionHandlerTest if PDO SQLite is not available

src/Symfony/Component/HttpFoundation/Tests/Session/Storage/Handler/PdoSessionHandlerTest.php

@@ -19,6 +19,10 @@ class PdoSessionHandlerTest extends \PHPUnit_Framework_TestCase
 
     protected function setUp()
     {
+        if (!class_exists('PDO') || !in_array('sqlite', \PDO::getAvailableDrivers())) {
+            $this->markTestSkipped('This test requires SQLite support in your environment');
+        }
+
         $this->pdo = new \PDO("sqlite::memory:");
         $sql = "CREATE TABLE sessions (sess_id VARCHAR(255) PRIMARY KEY, sess_data TEXT, sess_time INTEGER)";
         $this->pdo->exec($sql);