title: All images in /assets folder dissapear when I build with webpack
body: <p>Until now I worked in <strong><em>dev enviroment</em></strong>, but now I arrived into <strong><em>prod enviroment</em></strong>, and I run into this issue:</p>
  
  <p>some important details on the project:</p>
  
  <ul>
  <li><strong>Everything works</strong> fine when I run the project on <code>webpack-dev-server</code></li>
  <li>Its a <strong>React</strong> app </li>
  <li>I costumized <code>webpack.config</code> myself so maybe I have some mistakes <em>(not a create-react-app)</em></li>
  <li>My <code>/assets</code> folder has some images</li>
  <li>I have <code>font-awesome</code> installed</li>
  <li>I use <code>file-loader</code> to deal with <strong>font-awesome</strong> and <strong>all the images</strong></li>
  </ul>
  
  <p><strong>The problem:</strong> </p>
  
  <p>After I run build I loose all of the images I had in the <code>/assets</code> folder,
  and get to have only some <strong><em>font-awesome-webfonts</em></strong> files.</p>
  
  <p>I still get to have an <code>/assets</code> folder inside <code>/dist</code>, but my images are getting dropped of somewhere on the build proccess.</p>
  
  <p>I'm not sure why this happens, but I have a feeling that font-awesome's files runs over the rest of the files, but its just an assumption.</p>
  
  <p>Do you see what am I missing ?</p>
  
  <p><strong><em>my webpack.config.js:</em></strong></p>
  
  <pre><code>const path = require('path');
  const HtmlPlugin = require('html-webpack-plugin');
  const webpack = require('webpack');
  const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
  const AutoDllPlugin = require('autodll-webpack-plugin');
  
  // Development
  const APP_DIR = path.join(__dirname, 'src');
  const BUILD_DIR = path.join(__dirname, 'dist');
  const ASSETS_DIR = path.join(__dirname, 'src', 'assets');
  
  // Production
  const PROD_URL = '/portfolio/dist/';
  const PROD_ASSETS_DIR = PROD_URL+'assets';
  
  
  module.exports = {
      entry: {
          main: APP_DIR,   
      },
      output: {
          filename: 'app.js',
          path: BUILD_DIR,
          publicPath: PROD_URL
      },
      devServer: {
          historyApiFallback: true,
          compress: true,
          contentBase: ASSETS_DIR
      },
      module: {
          rules: [
              {
                  test: /\.jsx?$/,
                  use: 'babel-loader',
                  exclude: /node_modules/
              },
              {
                  test: /\.tsx?$/,
                  loader: 'ts-loader'
              },
              {
                  test: /\.css$/,
                  use: ["style-loader", "css-loader"]
              },
              {
                  test: /\.scss$/,
                  use: ["style-loader", "css-loader", "sass-loader"]
              },
              {
                  test: /.(png|gif|jpg|jpeg|ttf|otf|eot|svg|woff(2)?)(\?[a-z0-9]+)?$/,
                  use: [{
                    loader: 'file-loader',
                    options: {
                      name: '[name].[ext]',
                      outputPath: 'dist/assets/',    // where the fonts will go
                      publicPath: PROD_ASSETS_DIR       // override the default path
                    }
                  }]
                } 
          ]
      },
      plugins: [
          new HtmlPlugin({
              filename: 'index.html',
              template: './src/index.html'
          }),
  
          new AutoDllPlugin({
              inject: true,
              filename: '[name]_[hash].js',
              entry: {
                  vendor: [
                      'react',
                      'react-dom',
                      'react-router-dom',
                      'mobx', 
                      'mobx-react', 
                      'd3', 
                      // 'styled-component',
                      'lodash',
                      'topojson',
                      'font-awesome',
                      // 'react-flag-icon-css',
                      'react-chartjs-2',
                      'datamaps',
                      'chart.js'
                  ] 
              }
          }),
  
          new BundleAnalyzerPlugin({
              // Can be `server`, `static` or `disabled`.
              // In `server` mode analyzer will start HTTP server to show bundle report.
              // In `static` mode single HTML file with bundle report will be generated.
              // In `disabled` mode you can use this plugin to just generate Webpack Stats JSON file by setting `generateStatsFile` to `true`.
              analyzerMode: 'server',
              // Host that will be used in `server` mode to start HTTP server.
              analyzerHost: '127.0.0.1',
              // Port that will be used in `server` mode to start HTTP server.
              analyzerPort: 8888,
              // Path to bundle report file that will be generated in `static` mode.
              // Relative to bundles output directory.
              reportFilename: 'report.html',
              // Module sizes to show in report by default.
              // Should be one of `stat`, `parsed` or `gzip`.
              // See "Definitions" section for more information.
              defaultSizes: 'parsed',
              // Automatically open report in default browser
              openAnalyzer: false,
              // If `true`, Webpack Stats JSON file will be generated in bundles output directory
              generateStatsFile: false,
              // Name of Webpack Stats JSON file that will be generated if `generateStatsFile` is `true`.
              // Relative to bundles output directory.
              statsFilename: 'stats.json',
              // Options for `stats.toJson()` method.
              // For example you can exclude sources of your modules from stats file with `source: false` option.
              // See more options here: https://github.com/webpack/webpack/blob/webpack-1/lib/Stats.js#L21
              statsOptions: null,
              // Log level. Can be 'info', 'warn', 'error' or 'silent'.
              logLevel: 'info'
            })
      ],
  
      devtool: 'source-maps',
      resolve: {
          extensions: [".ts", ".tsx", ".js", ".jsx"]
      }
  }
  </code></pre>