title: webpack with Babel not working
body: <p>I run in the Windows command prompt : npm start</p>
  
  <p>and get:</p>
  
  <blockquote>
    <p>JavaScript-ES6@1.0.0 start C:\Dans\Courses\JavaScript-ES6
    webpack-dev-server</p>
  </blockquote>
  
  <p>× ｢wds｣: Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
   - configuration.module has an unknown property 'loaders'. These properties are valid:
     object { exprContextCritical?, exprContextRecursive?, exprContextRegExp?, exprContextRequest?, noParse?, rules?, defaultRules?, unknownContextCritical?, unknownContextRecursive?, unknownContextRegExp?, unknownContextRequest?, unsafeCache?, wrappedContextCritical?, wrappedContextRecursive?, wrappedContextRegExp?, strictExportPresence?, strictThisContextOnImports? }
     -> Options affecting the normal modules (<code>NormalModuleFactory</code>).</p>
  
  <p>npm ERR! Windows_NT 10.0.17134
  npm ERR! argv "C:\Program Files\nodejs\node.exe" "C:\Program Files\nodejs\node_modules\npm\bin\npm-cli.js" "start"
  npm ERR! node v6.10.0
  npm ERR! npm  v3.10.10
  npm ERR! code ELIFECYCLE
  npm ERR! JavaScript-ES6@1.0.0 start: <code>webpack-dev-server</code>
  npm ERR! Exit status 1
  npm ERR!
  npm ERR! Failed at the JavaScript-ES6@1.0.0 start script 'webpack-dev-server'.
  npm ERR! Make sure you have the latest version of node.js and npm installed.
  npm ERR! If you do, this is most likely a problem with the JavaScript-ES6 package,
  npm ERR! not with npm itself.
  npm ERR! Tell the author that this fails on your system:
  npm ERR!     webpack-dev-server
  npm ERR! You can get information on how to open an issue for this project with:
  npm ERR!     npm bugs JavaScript-ES6
  npm ERR! Or if that isn't available, you can get their info via:
  npm ERR!     npm owner ls JavaScript-ES6
  npm ERR! There is likely additional logging output above.</p>
  
  <hr>
  
  <p>My webpack.config.js file content:</p>
  
  <p>const path = require('path');</p>
  
  <pre><code>   module.exports = {
     entry: ['./app/index.js'],
     output: {
         path: path.resolve(__dirname, 'build'),
         filename: 'bundle.js'
     },
     module: {
         loaders: [
           {  
             loader: 'babel-loader',
             test: /\.js$/,
             exclude: /node_modules/
           }
          ]
     },
       devServer: {
          port: 3000,
          contentBase: './build',
          inline: true
      }
  }
  </code></pre>
  
  <hr>
  
  <p>My package.json file content:</p>
  
  <pre><code>{
    "name": "JavaScript-ES6",
    "version": "1.0.0",
    "description": "",
    "main": "index.js",
    "scripts": {
    "build": "webpack",
    "start": "webpack-dev-server"
   },
     "babel": {
     "presets": ["es2015"]
      },
    "keywords": [],
    "author": "",
    "license": "ISC",
    "devDependencies": {
      "babel-core": "^6.26.3",
      "babel-loader": "^7.1.4",
      "babel-polyfill": "^6.26.0",
      "babel-preset-es2015": "^6.24.1",
      "webpack": "^4.8.3",
      "webpack-cli": "^2.1.4",
      "webpack-dev-server": "^3.1.4"
    }
  }
  </code></pre>