title: electron-builder - only build for mac but set to build mac and win
body: <p>This is the first time I am building <code>electronjs</code> app so most probably I don't know what I am doing.</p>
  
  <p>I follow the instruction from the <a href="https://github.com/electron-userland/electron-builder" rel="noreferrer"><code>github</code></a> and <a href="https://medium.com/@jamzi/building-desktop-applications-with-electron-electron-builder-47484193cbcc" rel="noreferrer">this</a>.
  This is my <code>package.json</code>:</p>
  
  <pre><code>{
    "name": "ExampleApp",
    "productName": "ExampleApp",
    "version": "1.0.0",
    "description": "Fun app.",
    "license": "MIT",
    "repository": "user/repo",
    "author": {
      "name": "sooon",
      "email": "Example@gmail.com",
      "url": "Example.com"
    },
    "build": {
      "appId": "com. Example.ExampleApp",
      "mac": {
        "target": "dmg",
        "icon": "build/icon.png"
      },
      "win": {
        "target": "nsis",
        "icon": "build/icon.png"
      }
   },
    "scripts": {
      "test": "xo",
      "start": "electron .",
      "pack": "electron-builder --dir",
      "dist": "electron-builder"
    },
    "dependencies": {
      "electron-debug": "^1.0.0",
      "jquery": "^3.3.1"
    },
    "devDependencies": {
      "devtron": "^1.1.0",
      "electron": "^1.8.2",
      "electron-builder": "^19.56.0",
      "electron-packager": "^8.7.2",
      "xo": "^0.18.0"
    },
    "xo": {
      "envs": [
        "node",
        "browser"
      ]
    }
  }
  </code></pre>
  
  <p>As you can see I have <code>mac</code> and <code>win</code> in the <code>build</code> script. But when I run:</p>
  
  <pre><code>nom run dist
  </code></pre>
  
  <p>only <code>DMG</code> file (fully functional) is build. There is not trace of any work with <code>win</code> app. What had I miss out in  the setting?</p>
  
  <p>I am building this with my MacBook running on <code>10.12.6</code>. Is it only you can build for your own platform? Can <code>Mac</code> build for <code>Windows</code>?</p>
  
  <p><strong>Update01</strong>
  I took out:</p>
  
  <pre><code>"build": {
      "appId": "com.sooonism.pipidance",
      "mac": {
        "target": "dmg",
        "icon": "build/icon.png"
      },
      "win": {
        "target": "nsis",
        "icon": "build/icon.png"
      }
   },
  </code></pre>
  
  <p>from the <code>package.json</code> and it still build ok. That means the <code>build</code> script is located somewhere maybe?</p>