title: Webpack can't load packages from node_modules
body: <p>I am starting app with <a href="https://github.com/coryhouse/react-slingshot" rel="nofollow">react-slingshot</a> start kit. I wanted to load from node_modules normalize.css and react-toolbox but I am getting these errors during the build:</p>
  
  <pre><code>ERROR in ./~/normalize.css/normalize.css
  Module parse failed: /home/jules/projects/tourbnb-frontend/node_modules/normalize.css/normalize.css Line 9: Unexpected token {
  You may need an appropriate loader to handle this file type.
  |  */
  | 
  | html {
  |   font-family: sans-serif; /* 1 */
  |   -ms-text-size-adjust: 100%; /* 2 */
   @ ./src/index.js 29:0-24
  
  ERROR in ./~/react-toolbox/lib/app/App.js
  Module not found: Error: Cannot resolve 'file' or 'directory' ./style in /home/jules/projects/tourbnb-frontend/node_modules/react-toolbox/lib/app
   @ ./~/react-toolbox/lib/app/App.js 11:13-31
  </code></pre>
  
  <p>This is my index.js: </p>
  
  <pre><code>import React from 'react';
  import {render} from 'react-dom';
  import { Provider } from 'react-redux';
  import ToolboxApp from 'react-toolbox/lib/app';
  import App from './containers/App';
  import configureStore from './store/configureStore';
  import './styles/styles.scss'; //Yep, that's right. You can import SASS/CSS files too! Webpack will run the associated loader and plug this into the page.
  import 'normalize.css';
  
  const store = configureStore();
  
  render(
    &lt;Provider store={store}&gt;
      &lt;ToolboxApp&gt;
        &lt;App /&gt;
      &lt;/ToolboxApp&gt;
    &lt;/Provider&gt;, document.getElementById('app')
  );
  </code></pre>
  
  <p>And this is my webpack.config.js
      // For info about this file refer to webpack and webpack-hot-middleware documentation
      // Rather than having hard coded webpack.config.js for each environment, this
      // file generates a webpack config for the environment passed to the getConfig method.
      import webpack from 'webpack';
      import path from 'path';
      import ExtractTextPlugin from 'extract-text-webpack-plugin';</p>
  
  <pre><code>const developmentEnvironment = 'development' ;
  const productionEnvironment = 'production';
  const testEnvironment = 'test';
  
  const getPlugins = function (env) {
    const GLOBALS = {
      'process.env.NODE_ENV': JSON.stringify(env),
      __DEV__: env === developmentEnvironment
    };
  
    const plugins = [
      new webpack.optimize.OccurenceOrderPlugin(),
      new webpack.DefinePlugin(GLOBALS) //Tells React to build in prod mode. https://facebook.github.io/react/downloads.html
    ];
  
    switch (env) {
      case productionEnvironment:
        plugins.push(new ExtractTextPlugin('styles.css'));
        plugins.push(new webpack.optimize.DedupePlugin());
        plugins.push(new webpack.optimize.UglifyJsPlugin());
        break;
  
      case developmentEnvironment:
        plugins.push(new webpack.HotModuleReplacementPlugin());
        plugins.push(new webpack.NoErrorsPlugin());
        break;
    }
  
    return plugins;
  };
  
  const getEntry = function (env) {
    const entry = [];
  
    if (env === developmentEnvironment ) { // only want hot reloading when in dev.
      entry.push('webpack-hot-middleware/client');
    }
  
    entry.push('./src/index');
  
    return entry;
  };
  
  const getLoaders = function (env) {
    const loaders = [{ test: /\.js$/, include: path.join(__dirname, 'src'), loaders: ['babel', 'eslint'] }];
  
    if (env === productionEnvironment ) {
      // generate separate physical stylesheet for production build using ExtractTextPlugin. This provides separate caching and avoids a flash of unstyled content on load.
      loaders.push({
        test: /(\.css|\.scss)$/,
        include: path.join(__dirname, 'src'),
        loader: ExtractTextPlugin.extract("css?sourceMap!sass?sourceMap")
      });
    } else {
      loaders.push({
        test: /(\.css|\.scss)$/,
        include: path.join(__dirname, 'src'),
        loaders: ['style', 'css?sourceMap', 'sass?sourceMap']
      });
    }
  
    return loaders;
  };
  
  function getConfig(env) {
    return {
      debug: true,
      devtool: env === productionEnvironment  ? 'source-map' : 'cheap-module-eval-source-map', // more info:https://webpack.github.io/docs/build-performance.html#sourcemaps and https://webpack.github.io/docs/configuration.html#devtool
      noInfo: true, // set to false to see a list of every file being bundled.
      entry: getEntry(env),
      target: env === testEnvironment ? 'node' : 'web', // necessary per https://webpack.github.io/docs/testing.html#compile-and-test
      output: {
        path: __dirname + '/dist', // Note: Physical files are only output by the production build task `npm run build`.
        publicPath: '',
        filename: 'bundle.js'
      },
      plugins: getPlugins(env),
      module: {
        loaders: getLoaders(env)
      }
    };
  }
  
  export default getConfig;
  </code></pre>
  
  <p>What might be the problem? Thanks.</p>