client.py get_oauth_token() raises exception on 301 response

[penguin-wrangler]

https://github.com/google/gdata-python-client/blob/master/src/gdata/client.py#L577

Google is returning a 301 response (Moved Temporarily) aka Redirect. The get_oauth_token code treats anything other than 200 as an error, and does not follow the redirect, thus authentication is broken.