webpack.config.js

const plugins = [
  // extract vendor and webpack's module manifest
  new webpack.optimize.CommonsChunkPlugin({
    names: [ 'vendor', 'manifest' ],
    minChunks: Infinity
  }),
  // extract common modules from all the chunks (requires no 'name' property)
  new webpack.optimize.CommonsChunkPlugin({
    async: true,
    children: true,
    minChunks: 4
  })
];