Warning: require_once(__DIR__/../vendor/autoload.php) [function.require-once]: failed to open stream: No such file or directory in /home/babak/symfony/2/vendor/doctrine/data-fixtures/tests/bootstrap.php on line 21

Fatal error: require_once() [function.require]: Failed opening required '__DIR__/../vendor/autoload.php' (include_path='.:/usr/share/php:/usr/share/pear') in /home/babak/symfony/2/vendor/doctrine/data-fixtures/tests/bootstrap.php on line 21