Travis: Don't ignore Node 5/OSX builds anymore
Travis: Don't ignore Node 5/OSX builds anymore

Closes #598.

electron-userland/electron-packager,malept/electron-packager,electron-userland/electron-packager,Goobaroo/electron-packager,Goobaroo/electron-packager,maxogden/electron-packager,malept/electron-packager