MAGETWO-56126: Login failed after new custom attribute was added

- fix static test

Author: cpartica

app/code/Magento/Customer/Test/Unit/Model/CustomerAuthUpdateTest.php

@@ -3,7 +3,7 @@
  * Copyright © 2016 Magento. All rights reserved.
  * See COPYING.txt for license details.
  */
-namespace Magento\Test\Unit\Customer\Model;
+namespace Magento\Customer\Test\Unit\Model;
 
 use Magento\Customer\Model\CustomerAuthUpdate;