从Symfony 3发出PSR-7响应

Question

I am attempting to emit and receive PSR-7 style responses in Symfony 3.2.6 I have been attempting to follow the original post from dunglas on the subject which makes it seem rather simple. using-psr-7-in-symfony

I have added

"symfony/psr-http-message-bridge": "v1.0.0", "zendframework/zend-diactoros": "1.3.10"

to my composer.json

and my controller is the following:

namespace AppBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Zend\Diactoros\Response;

class DefaultController extends Controller
{

    public function isAllowedAction()
    {
        $rep = ['status' => 1, 'message' => 'access granted'];
        $response = new Response();
        $response->getBody()->write(json_encode($rep));
        return $response;
    }
}

When I try this, I get the following exception in the browser: The controller must return a response (Object(Zend\Diactoros\Response) given).

I thought that the Zend\Diactoros\Response object should be compatible per the example in the article. It references the sensio/framework-extra-bundle as making it possible so I'm wondering if there is a config I'm missing.