Cloudpathlib

- Added support for Google Cloud Storage. Instantiate with URIs prefixed by `gs://` or explicitly using the `GSPath` class. ([113](https://github.com/drivendataorg/cloudpathlib/pull/113) thanks to [wolfgangwazzlestrauss](https://github.com/wolfgangwazzlestrauss))
- Changed backend logic to reduce number of network calls to cloud. This should result in faster cloud path operations, especially when dealing with many small files. ([110](https://github.com/drivendataorg/cloudpathlib/issues/110), [#111](https://github.com/drivendataorg/cloudpathlib/pull/111))

- Fixed `CloudPath` instantiation so that reinstantiating with an existing `CloudPath` instance will reuse the same client, if a new client is not explicitly passed. This addresses the edge case of non-idempotency when reinstantiating a `CloudPath` instance with a non-default client. ([104](https://github.com/drivendataorg/cloudpathlib/pull/104))

- Fixed a character-encoding bug when building from source on Windows. ([98](https://github.com/drivendataorg/cloudpathlib/pull/98))

- Initial release of cloudpathlib with support for Amazon S3 and Azure Blob Storage! 🎉