Make Pyrad compatible with Windows?

[jfigui]

Recently, a student wanted to use Pyrad but he could only work with his personal computer, in Windows, and he found out that Pyrad was not Windows compatible. Given how the package is built it should not be terribly difficult to make it Windows compatible but we have to see whether that was a niche case or it is worth the effort.

[wolfidan]

Currently working on using pathlib for all path generations