Let OAuth2Decorator take a list of scopes.

Reviewed in http://codereview.appspot.com/5277045/
diff --git a/tests/test_oauth2client_file.py b/tests/test_oauth2client_file.py
index 4776404..de5fcf2 100644
--- a/tests/test_oauth2client_file.py
+++ b/tests/test_oauth2client_file.py
@@ -152,7 +152,7 @@
         FILENAME,
         'some_client_id',
         'user-agent/1.0',
-        'some-scope')
+        ['some-scope', 'some-other-scope'])
 
     credentials = store.get()
     self.assertEquals(None, credentials)
@@ -175,7 +175,7 @@
         FILENAME,
         credentials.client_id,
         credentials.user_agent,
-        'some-scope')
+        ['some-scope', 'some-other-scope'])
 
     store.put(credentials)
     credentials = store.get()