fix CustomerCest

tests/functional/Customer/CustomerCest.php

@@ -37,7 +37,7 @@ class CustomerCest
     public function updateCustomerAddress(FunctionalTester $I)
     {
         $I->wantTo('Instantiate a european faker factory to have the vat provider available');
-        $faker = Faker\Factory::create('at_AT');
+        $faker = \Faker\Factory::create('at_AT');
 
         $formCssSelector = '#customer-address-form';