[WIP] Proof of concept fsspec integration

[jayqi]

Implementation of FsspecClient and FsspecPath that work with an fsspec concrete filesystem implementation.

Follow up on #96

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• New abstract FsspecClient, FsspecPath classes. Each registered implementation in fsspec.registry has subclasses autogenerated, e.g., S3Path, GCSPath, HTTPPath.
• FsspecPath will automatically dispatch to correct subclass, the same way CloudPath does. This dispatching is isolated to FsspecPath; CloudPath still only dispatches to original implementations.
  • Running environment variable FSSPEC_MODE=1 will replace CloudPath's dispatching so that it will dispatch to fsspec subclasses instead of the normal ones.
• New extras.
  • [fsspec] will install fsspec.
  • Each extras from fsspec has been copied to [fsspec-<name>], e.g.fsspec-s3fs.
  • [fsspec-all] will install all fsspec extras.
  • original [all] does not include any fsspec extras

[github-actions]

🚀 Deployed on https://deploy-preview-109--gallant-agnesi-5f7bb3.netlify.app

[codecov]

Codecov Report

Merging #109 (ba3d9f3) into master (8b230c3) will decrease coverage by 12.3%.
The diff coverage is 15.7%.

@@            Coverage Diff            @@
##           master    #109      +/-   ##
=========================================
- Coverage    91.4%   79.1%   -12.4%     
=========================================
  Files           8      12       +4     
  Lines         680     792     +112     
=========================================
+ Hits          622     627       +5     
- Misses         58     165     +107     

Impacted Files	Coverage Δ
cloudpathlib/fsspec/__init__.py	0.0% <0.0%> (ø)
cloudpathlib/fsspec/fsspecclient.py	0.0% <0.0%> (ø)
cloudpathlib/fsspec/fsspecpath.py	0.0% <0.0%> (ø)
cloudpathlib/fsspec/implementations.py	0.0% <0.0%> (ø)
cloudpathlib/cloudpath.py	89.8% <100.0%> (+0.1%)	⬆️

[pjbull]

See discussion in #96