Missing Python dependencies

[rljacobson]

Packaide depends on the Python libraries shapely and svgelements. Additionally, the tests depend on the parameterized Python library.

[DanielLiamAnderson]

Version 2 of the library is in the works and almost finished (see https://github.com/DanielLiamAnderson/Packaide/tree/v2), and will address this and in general make the library much easier to build and install. Unfortunately I can't release it just yet because of some bugs on non-Linux OSes (similar to #3), and I don't have a MacOS machine to debug on.