title: React Jest es6 (rest spread operator) babel configuration not working
body: <p>I am try create app with <code>react-tool-box</code>. Also I try use <code>Jest</code> for testing, </p>
  
  <p>but get this test fails. It look like es6 configuration problem for <code>Jest</code>.  </p>
  
  <p>● Test suite failed to run</p>
  
  <pre><code>/home/user/project/react-tool-box/react-toolbox-example/src/frontend/components/PurpleAppBar.js: Unexpected token (5:34)
      3 | import theme from './PurpleAppBar.css';
      4 | 
    &gt; 5 | const PurpleAppBar = ({ children, ...other }) =&gt; (
        |                                   ^
      6 |   &lt;AppBar {...other} theme={theme}&gt;
      7 |     Hello developer!
      8 |     {children}
  </code></pre>
  
  <p>my <code>jest.config.js</code>:</p>
  
  <pre><code>{
  "moduleFileExtensions": [
      "js",
      "jsx"
  ],
  "scriptPreprocessor": "&lt;rootDir&gt;/node_modules/babel-jest",
  "moduleNameMapper": {
      "App": "&lt;rootDir&gt;/src/frontend/components/App.js"
  }
  </code></pre>
  
  <p>}</p>
  
  <p>my <code>.bablerc</code>:</p>
  
  <pre><code> {
    "presets": [
       "react",
       "es2015"
    ]
  }
  </code></pre>
  
  <p>and <code>package.json</code> scripts:</p>
  
  <pre><code>...    
  "scripts": {
          "start": "node_modules/.bin/cross-env NODE_ENV=development node_modules/.bin/webpack-dev-server --colors --config webpack.config.js",
          "build": "node_modules/.bin/cross-env NODE_ENV=production UV_THREADPOOL_SIZE=100 webpack --config webpack.config.js",
          "deploy": "gh-pages -d build",
          "test": "jest --config jest.config.js"
        },
  ...
  </code></pre>