Mac build for Windows

[michaelb-01]

I'm able to build my app for a mac from a mac but i'm trying to build for windows but it doesn't seem to work. This is my Meteor.settings.electron file:

{
  "electron": {
    "name": "Test",
    "icon": {
      "darwin": "private/MyApp.icns",
      "win32": "private/MyApp.ico"
    },
    "version": "0.1.0",
    "description": "Test app",
    "rootUrl": "https://myapp.com",
    "launchPath": "/app/landing",
    "downloadUrls": {
      "win32": "https://myapp.com/download/win/",
      "darwin": "https://myapp.com/download/osx/{{version}}/MyApp.zip"
    },
    "sign": "Developer ID Application: ...",
    "height": 768,
    "width": 1024,
    "frame": true,
    "title-bar-style": "hidden",
    "resizable": true,
    "protocols": [{
      "name": "MyApp",
      "schemes": ["myapp"]
    }],
    "appSrcDir": "private/app",
    "builds": [
      {"platform": "win32",
       "arch": "ia32"}
    ]
  }
}