title: bundle.js:1 SyntaxError: Unexpected keyword 'const'. Const declarations are not supported in strict mode
body: <p>I have a site that works fine on my iPad and desktop, but not on other devices I am testing at browserstack.com  (eg Safari on iPhone 6S) and my iPhone 4.  </p>
  
  <p>Visually, it just looks like the <code>CSS</code> and <code>JS</code> is just not loading.  </p>
  
  <p>The dev tools console error at browserstack is:</p>
  
  <blockquote>
    <p>bundle.js:1 SyntaxError: Unexpected keyword 'const'. Const
    declarations are not supported in strict mode.</p>
  </blockquote>
  
  <p>My <code>webpack.config.json</code> has this rule:</p>
  
  <pre><code>rules: [{
          test: /\.js$/,
          exclude: /(node_modules)/,
          use: {
              loader: "babel-loader",
              options: {
                  presets: ["env", "stage-0"]
              }
          }
      },
  </code></pre>
  
  <p>And <code>.babelrc</code> is:</p>
  
  <pre><code>{
      "presets": [
          "env",
          "stage-0"
      ]
  }
  </code></pre>
  
  <p>And <code>package.json</code> has:</p>
  
  <pre><code>"devDependencies":
  {
      "babel-cli": "^6.26.0",
      "babel-core": "^6.26.3",
      "babel-loader": "^7.1.4",
      "babel-preset-env": "^1.7.0",
      "babel-preset-stage-0": "^6.24.1",
      "css-loader": "^0.28.11",
      "expose-loader": "^0.7.5",
      "file-loader": "^1.1.11",
      "less": "^3.0.4",
      "less-loader": "^4.1.0",
      "style-loader": "^0.21.0",
      "uglifyjs-webpack-plugin": "^1.2.5",
      "uikit": "^3.0.0-rc.16",
      "url-loader": "^1.0.1",
      "webpack": "^4.19.1",
      "webpack-cli": "^2.1.5"
  }
  </code></pre>