Fix static test.

Author: nmalevanec

app/code/Magento/Customer/Controller/Ajax/Logout.php

@@ -7,13 +7,15 @@
 
 namespace Magento\Customer\Controller\Ajax;
 
+use Magento\Framework\App\Action\HttpGetActionInterface;
+
 /**
  * Logout controller
  *
  * @method \Magento\Framework\App\RequestInterface getRequest()
  * @method \Magento\Framework\App\Response\Http getResponse()
  */
-class Logout extends \Magento\Framework\App\Action\Action
+class Logout extends \Magento\Framework\App\Action\Action implements HttpGetActionInterface
 {
     /**
      * @var \Magento\Customer\Model\Session