title: How to write webpack.config.js when set more param?
body: <p>I want to handle my jsx code, so I write webpakc.config.js like this:</p>
  
  <pre class="lang-js prettyprint-override"><code>{
      test: /\.js$/,
      loaders: ['react-hot', 'babel-loader?presets[]=es2015'],
      exclude: /node_modules/
  }
  </code></pre>
  
  <p>But it didn't handle my jsx code and throw an error like this:
  <a href="http://i.stack.imgur.com/8pW8u.jpg">The error threw in terminal</a></p>
  
  <p>By Google I find I need to add <code>presets['react']</code> to my config file. So I update config like this:</p>
  
  <pre class="lang-js prettyprint-override"><code>{
      test: /\.js$/,
      loaders: ['react-hot', 'babel'],
      query: {
          presets: ['react', 'es2015']
      },
      exclude: /node_modules/
  }
  </code></pre>
  
  <p>But it threw another error:
  <a href="http://i.stack.imgur.com/VR5kE.jpg">A new error threw after update config file</a></p>
  
  <p>I am a fresher in webpack, What should I do?</p>