FIX ERROR, Filter the versions when getting the latest version

[1j01]

Sort of fixes #51 I guess.

[gabepaez]

Thanks @1j01, but I think your original idea was better. I gave it a stab (eae353b). I think that eliminating the dependency on the unofficial nodewebkit module is going to be less error prone and keep us in true sync with official versions coming out of node-webkit.