after middleware and cookie destroy

boostrap.php

$app->get('/logout', function() use ($app) {
    if ($app['session']->isStarted()) {
        $app['session']->clear();
    }
    return $app->redirect("/");
})
->after(function(\Symfony\Component\HttpFoundation\Request $request,
    \Symfony\Component\HttpFoundation\Response $response) use ($app) {
    $response->headers->clearCookie($app['session']->getName());
});