[gnome-online-accounts] google: Update README

[Debarshi Ray <debarshir src gnome org>]

commit 8b7ec2860da02a3ac8cbc1ac42a773a084a2c965
Author: Debarshi Ray <debarshir gnome org>
Date:   Thu Jun 19 13:30:39 2014 +0200

    google: Update README
    
    Sometimes the documentation does not mention the OAuth2 scopes that
    need to be specified in the sources. Mention some of the third-party
    sites that can be useful to overcome that.
    
    Fixes: https://bugzilla.gnome.org/693689

 README |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/README b/README
index 1213ad4..829046d 100644
--- a/README
+++ b/README
@@ -43,6 +43,11 @@ https://developers.google.com/picasa-web/docs/2.0/developers_guide_protocol
 https://developers.google.com/talk/jep_extensions/oauth
 https://developers.google.com/cloud-print/docs/devguide
 
+Sometimes the documentation does not mention the OAuth2 scopes that need to be
+specified in the source code. In such cases, the following can be useful:
+https://developers.google.com/oauthplayground/
+https://discovery-check.appspot.com/
+
 Notes:
 We are allowed to embed the client_secret in the source code. See
 https://developers.google.com/accounts/docs/OAuth2InstalledApp#overview