Alternative to unzip.exe

[Montoya]

Hi, I noticed you are using unzip.exe to handle the unzip method on Windows. Have you considered a pure javascript solution to avoid this dependency? I am using adm-zip on a nw.js project and it works perfectly on any platform, not just windows. Have a look!

[adam-lynch]

I'm open to it. I don't have the time right now. A pull-request would be great 😃