Implement the Zip package type
AndFeathers can load archives from an existing directory
Reorganize specs
Make from_path behavior a little better defined
Remove Archive. Everything is a Directory or File
Make directory names consistent
Track files and directories separately
Store files and directories in a Hash
Two directories can be unioned

Unions overwrite duplicate files on the left with files from the right,
and merge duplicate directory paths.
Re-introduce Archive as the root object

I'm not sure how to describe what's going on, but the Archive is
responsible for looking like an ordinary directory, but operates in such
a way that every time we work with an Archive, we're working with a
clean slate. When we want to turn the Archive into an IO stream, the
Archive merges all of its clean slates together to form the final
picture.
Remove unused Enumerable
Update documentation
Test writing archives to disk