title: Error using Google Assistant Library with Raspberry Pi 3 and Python (Credentials not accepted)
body: <p>I successfully managed to get Google's Assistant working on my Raspberry Pi 3. It works by using </p>
  
  <pre><code>google-assistant-demo --d device_id1234
  </code></pre>
  
  <p>Now I want to get access with python to turn on/off an LED when a certain command is recognized. Unfortunately the page I followed isn't free, so I can't provide a link. The problematic part of my code is the following:</p>
  
  <pre><code>def main():
     parser = argparse.ArgumentParser(
         formatter_class=argparse.RawTextHelpFormatter)
     parser.add_argument('--credentials', type=existing_file,
                         metavar='OAUTH2_CREDENTIALS_FILE',
                         default=os.path.join(
                             os.path.expanduser('~/.config'),
                             'google-oauthlib-tool',
                             'credentials.json'
                         ),
                         help='Path to store and read OAuth2 credentials')
     args = parser.parse_args()
  
  
     with open(args.credentials, 'r') as f:
         credentials = google.oauth2.credentials.Credentials(token=None,
                                                             **json.load(f))
  
         with Assistant(credentials) as assistant:
             print("Warte auf Hotword")
             for event in assistant.start():
                 process_event(event, assistant)
  </code></pre>
  
  <p>and when I run the script by</p>
  
  <pre><code>python assistant.py --credentials client_secret_blabla.json
  </code></pre>
  
  <p>it throws the error</p>
  
  <pre><code>Traceback (most recent call last):
     File "assistant.py", line 137, in &lt;module&gt;
        main()
     File "assistant.py", line 128, in main
        **json.load(f)
  TypeError: __init__() got an unexpected keyword argument 'installed'
  </code></pre>
  
  <p>I tried to reinstall everything and also redownloaded the json file. Obviously the json doesn't get recognized properly, but I don't have any clue what to do. My JSON looks like this:</p>
  
  <pre><code>{"installed":{"client_id":"XXX.apps.googleusercontent.com","project_id":"dotted-nature-182957","auth_uri":"https://accounts.google.com/o/oauth2/auth","token_uri":"https://accounts.google.com/o/oauth2/token","auth_provider_x509_cert_url":"https://www.googleapis.com/oauth2/v1/certs","client_secret":"XXX","redirect_uris":["urn:ietf:wg:oauth:2.0:oob","http://localhost"]}}
  </code></pre>
  
  <p>here is what the Credentials class is expecting:
  <a href="http://google-auth.readthedocs.io/en/latest/reference/google.oauth2.credentials.html" rel="nofollow noreferrer">http://google-auth.readthedocs.io/en/latest/reference/google.oauth2.credentials.html</a></p>
  
  <p>I hope you guys can help me with this. Thanks a lot in advance!</p>