metadata_manager: make RemoteInfo serializable

metadata_manager/versions_fetcher.py

@@ -36,6 +36,12 @@ class RemoteInfo:
         self.name = name
         self.url = url
 
+    def to_dict(self):
+        return {
+            'name': self.name,
+            'url': self.url,
+        }
+
 
 class VersionsFetcher:
     """