Patch-Magento_Directory_M2.1-zip-codes.patch

--- Model/Country/Postcode/Config/Reader.php	2017-12-20 10:51:26.718397048 +0300
+++ Model/Country/Postcode/Config/Reader.php	2017-12-20 10:53:58.342135861 +0300
@@ -12,7 +12,10 @@
      *
      * @var array
      */
-    protected $_idAttributes = ['/config/zip' => 'countryCode'];
+    protected $_idAttributes = [
+        '/config/zip' => 'countryCode',
+        '/config/zip/codes/code' => 'id',
+    ];
 
     /**
      * Construct the FileSystem Reader Class