Added support for Windows

The biggest issue in this module was that Windows uses a `;` to separate paths instead of `:`.
These changes should help with https://github.com/Strider-CD/strider/issues/326
I just threw a quick console.log in to see what was going on:
path: undefined
Path: my;actual;path
PATH: undefined
I spit those out before starting strider, and they were all the same value, so something must be getting messed up elsewhere on Windows