message: add dep for building on windows
diff: "devDependencies": {
  "electron": "1.5.1",
  "electron-builder": "^12.3.1",
  - "electron-packager": "^8.5.1"
  + "electron-packager": "^8.5.1",
  + "electron-builder-squirrel-windows": "^12.3.0"
  },
  "dependencies": {
  "electron-squirrel-startup": "^1.0.0"
  