title: clean-webpack-plugin only accepts an options object
body: <p>I'm getting</p>
  
  <blockquote>
    <p>Error: clean-webpack-plugin only accepts an options object. See:
      <a href="https://github.com/johnagan/clean-webpack-plugin#options-and-defaults-" rel="noreferrer">https://github.com/johnagan/clean-webpack-plugin#options-and-defaults-</a></p>
  </blockquote>
  
  <p>My Webpack.config.js file looks like this:</p>
  
  <pre><code>const path = require('path');
  const webpack = require('webpack');
  const ExtractTextPlugin = require('extract-text-webpack-plugin');
  const CleanWebpackPlugin = require('clean-webpack-plugin');
  const CopyWebpackPlugin = require('copy-webpack-plugin');
  const HtmlWebpackPlugin = require('html-webpack-plugin');
  
  var plugins = [
      new CleanWebpackPlugin(['dist'], {}),
      new webpack.optimize.DedupePlugin(),
      new webpack.optimize.OccurenceOrderPlugin(),
      new CopyWebpackPlugin([{
          from: './src/images/',
          to: './images/'
      }]),
      new HtmlWebpackPlugin({
          inject: false,
          template: 'src/index.html'
      })
  ];
  
  var config = {
      entry: [
          './src/js/main.js'
      ],
  
      output: {
          path: path.join(__dirname, 'dist'),
          publicPath: '/',
          filename: 'js/bundle.js',
      },
  
      plugins: plugins.concat([
          new ExtractTextPlugin('css/bundle.css'),
          //new webpack.optimize.UglifyJsPlugin(require('./uglifyjs.json'))
      ]),
      devServer: {
          inline: true,
          port: 8080
      },
  
      module: {
          loaders: [{
              test: /\.jsx?$/,
              exclude: /node_modules/,
              include: path.join(__dirname, 'src'),
              loader: 'babel',
              query: {
                  presets: ['react', 'es2015']
              }},
              {
                  test: /.s?css$/,
                  include: path.join(__dirname, 'src'),
                  loader: ExtractTextPlugin.extract('style', [
                      'css?sourceMap',
                      'postcss',
                      'sass?sourceMap'
                  ])
              },
              {
                  test: /\.css$/,
                  include: path.join(__dirname, 'node_modules'),
                  loader: 'style!css'
              }
          ]
      },
      postcss: function() {
          return [
              require('autoprefixer')({
                  browsers: ['last 2 versions']
              })
          ];
      }
  }
  module.exports = config;
  </code></pre>