title: Browser debugger not working with Webpack 2 and webpack-dev-server
body: <p>I've spent last few hours to set up a new project utilizing Webpack 2 and Babel 6.</p>
  
  <p>The problem I have is non working debugger (any browser). Breakpoints are simply ignored. Using <code>debugger;</code> works fine but browser does not breaks execution exactly in that line.</p>
  
  <p><code>webpack.config.js:</code></p>
  
  <pre><code>const path = require("path");
  
  module.exports = {
      entry: path.resolve(__dirname, "src", "index.js"),
      output: {
          filename: "app.js",
          path: path.resolve(__dirname, "dist")
      },
      module: {
          rules: [{
              test: /\.js$/,
              exclude: /node_modules/,
              loader: "babel-loader"
          }]
      },
      devServer: {
          contentBase: path.resolve(__dirname, "dist")
      }
  };
  </code></pre>
  
  <p><code>.babel.rc:</code></p>
  
  <pre><code>{
    "presets": [
      "latest"
    ]
  }
  </code></pre>
  
  <p>I'm running the whole thing with <code>webpack-dev-server -d</code></p>