Extend Client.validate_scopes() to take request argument

.eggs/README.txt

@@ -0,0 +1,6 @@
+This directory contains eggs that were downloaded by setuptools to build, test, and run plug-ins.
+
+This directory caches those eggs to prevent repeated downloads.
+
+However, it is safe to delete this directory.
+

flask_oauthlib/provider/oauth2.py

@@ -949,7 +949,7 @@ def validate_scopes(self, client_id, scopes, client, request,
                         *args, **kwargs):
         """Ensure the client is authorized access to requested scopes."""
         if hasattr(client, 'validate_scopes'):
-            return client.validate_scopes(scopes)
+            return client.validate_scopes(scopes, request, *args, **kwargs)
         return set(client.default_scopes).issuperset(set(scopes))
 
     def validate_user(self, username, password, client, request,