Restore Folder pickle forward/backward compatibility with 3.12.0
Restore Folder pickle forward/backward compatibility with 3.12.0. Fixes #1
Restore Folder pickle forward/backward compatibility with 3.12.0. Fixes #1
PEP-8ify additions as recommended by the pep8 tool.
Merge pull request #2 from NextThought/master

Restore ``Folder`` pickle forward/backward compatibility with 3.12.0. Fixes #1