MAGETWO-71257: Need to disable module output

Author: Eric Bohanon

app/code/Magento/Wishlist/Test/Unit/Model/Rss/WishlistTest.php

@@ -128,6 +128,7 @@ public function testGetRssData()
         );
         $customerServiceMock = $this->createMock(\Magento\Customer\Api\Data\CustomerInterface::class);
         $wishlistSharingUrl = 'wishlist/shared/index/1';
+        $locale = 'en_US';
         $productUrl = 'http://product.url/';
         $productName = 'Product name';