support for gcs buckets like dolt cli utility

`dolt` cli client can add remotes with gcspath or local paths as well but doltpy does not support gcs paths

```
File "/usr/local/lib/python3.8/dist-packages/doltcli/dolt.py", line 274, in __init__
python-BaseException
raise ValueError(f"{self.repo_dir} is not a valid Dolt repository")
ValueError: gs://nom-ml-dummy-bucket-01/dummy_dir/dolt_cloud is not a valid Dolt repository
```

is there a plan to include it or maybe piece of code you can refer to?