First integration. BitPay invoice generation is ready. Fake responses from amazon

src/js/services/storageService.js

@@ -317,6 +317,18 @@ angular.module('copayApp.services')
         });
       });
     };
+    
+    root.setAmazonGiftCards = function(network, gcs, cb) {
+      storage.set('amazonGiftCards-' + network, gcs, cb);
+    };
+
+    root.getAmazonGiftCards = function(network, cb) {
+      storage.get('amazonGiftCards-' + network, cb);
+    };
+
+    root.removeAmazonGiftCards = function(network, cb) {
+      storage.remove('amazonGiftCards-' + network, cb);
+    };
 
     return root;
   });