Update pb_win.go

Don't use `github.com/AllenDang/w32` because 

- Too big for such a simple task 
- Issues using it on windows and after investigation and found [Unable to build w32](https://github.com/AllenDang/w32/issues/34)
- Bug not relating to screen size can make your whole project fail to install

Wrote a small package to do this [github.com/olekukonko/ts](github.com/olekukonko/ts) and you are welcome as contributor 

Tested on windows & linux