Add support for using local FS operations in place of GCS commands. This is useful for development and testing, as well as for embedded uses that want to use a bucket API.
[x] Add BucketClient abstraction
[x] Implement GCS bucket client
[x] Implement FS bucket client
[x] Run tests against all adapters using pytest.parametrize
[x] Add API for controlling the use of file-system adapter
Add support for using local FS operations in place of GCS commands. This is useful for development and testing, as well as for embedded uses that want to use a bucket API.