title: Webpack 2 eslint-loader auto fix
body: <p>In webpack 1.x I could use the eslint property in my webpack config to enable autofixing my linting errors using:</p>
  
  <pre><code>...
  
  module.exports = {
    devtool: 'source-map',
    entry: './src/app.js',
    eslint: {
      configFile: '.eslintrc',
      fix: true
    },
  
  ...
  </code></pre>
  
  <p>However, in webpack 2.x, thusfar I have been unable to use the auto fix functionality, because I don't know where to set it in my webpack config. Using the eslint property in my webpack configFile throws an <code>WebpackOptionsValidationError</code>.</p>