symfony_http_basic_logout.php

src/AppBundle/EventListener/LogoutListener.php:
//
<?php

    namespace AppBundle\EventListener;

    use Symfony\Component\HttpFoundation\RedirectResponse;
    use Symfony\Component\HttpFoundation\Request;
    use Symfony\Component\Security\Http\Logout\LogoutSuccessHandlerInterface;

    class LogoutListener implements  LogoutSuccessHandlerInterface
    {
        public function onLogoutSuccess(Request $request)
        {
            return new RedirectResponse('http://logout@'.$request->getHttpHost());
        }
    }

app/config/services.yml:
//
services:
    logout_listener:
        class: AppBundle\EventListener\LogoutListener

app/config/routing.yml:
//
logout:
    path: /logout

app/config/security.yml:
//
security:
    firewalls:
        # disables authentication for assets and the profiler, adapt it according to your needs
        dev:
            pattern: ^/(_(profiler|wdt)|css|images|js)/
            security: false

        main:
            anonymous: ~
            # activate different ways to authenticate

            http_basic: ~
            # http://symfony.com/doc/current/book/security.html#a-configuring-how-your-users-will-authenticate

            logout:
                path:   /logout
                target: /
                success_handler: logout_listener