Secrets Error from oauth2client deprecation

[sugiyama34]

Recently, Google deprecated the oauth2client. https://google-auth.readthedocs.io/en/latest/oauth2client-deprecation.html
So, we have error when we try to use d2g.upload and g2d.download with the below Error message.

I think it is possible to reproduce the below error when we run the below code in Google Colab.

(Please replace 'XXXXXX' in gfile.)

from google.colab import auth
auth.authenticate_user()

from google.auth import default
credentials, _ = default()

from df2gspread import df2gspread as d2g
from df2gspread import gspread2df as g2d
import numpy as np
import pandas as pd

df = pd.DataFrame(np.arange(16).reshape(4, 4))

d2g.upload(df=df, gfile='XXXXXXXXXXXXXXXXXXXXXXXXXX', wks_name='test', credentials=credentials, row_names=False)

↓ Error message

Invalid credentials supplied. Will generate from default token.
/usr/local/lib/python3.7/dist-packages/oauth2client/_helpers.py:255: UserWarning: Cannot access /root/.oauth/drive.json: No such file or directory
  warnings.warn(_MISSING_FILE_MESSAGE.format(filename))
---------------------------------------------------------------------------
FileNotFoundError                         Traceback (most recent call last)
[/usr/local/lib/python3.7/dist-packages/oauth2client/clientsecrets.py](https://localhost:8080/#) in _loadfile(filename)
    120     try:
--> 121         with open(filename, 'r') as fp:
    122             obj = json.load(fp)

FileNotFoundError: [Errno 2] No such file or directory: '/root/.gdrive_private'

During handling of the above exception, another exception occurred:

InvalidClientSecretsError                 Traceback (most recent call last)
6 frames
[/usr/local/lib/python3.7/dist-packages/oauth2client/clientsecrets.py](https://localhost:8080/#) in _loadfile(filename)
    123     except IOError as exc:
    124         raise InvalidClientSecretsError('Error opening file', exc.filename,
--> 125                                         exc.strerror, exc.errno)
    126     return _validate_clientsecrets(obj)
    127 

InvalidClientSecretsError: ('Error opening file', '/root/.gdrive_private', 'No such file or directory', 2)