docs: def GetPublicCert(self):
      """Download Gitkit public cert.
  
      Returns:
        dict of public certs.
      """
  
      cert_url = self.google_api_url + 'publicKeys'
  
      resp, content = self.http.request(cert_url)
      if resp.status == 200:
        return simplejson.loads(content)
      else:
        raise errors.GitkitServerError('Error response for cert url: %s' %
                                       content)