Updated webfeed's repository

pubspec.yaml

@@ -5,8 +5,8 @@ homepage: https://github.com/witochandra/webfeed
 environment:
   sdk: '>=2.12.0 <3.0.0'
 dependencies:
-  xml: "^5.0.2"
-  intl: "^0.17.0"
+  xml: "^6.1.0"
+  intl: "^0.18.0"
 dev_dependencies:
   test: ^1.3.0
   http: "^0.13.0"