core/webpack.config.js

const path = require('path');
const webpack = require('webpack');
const CleanWebpackPlugin = require('clean-webpack-plugin');
const ExtractTextPlugin = require("extract-text-webpack-plugin");

module.exports = {
  entry: './src/index.js',
  output: {
    filename: '[name].bundle.js',
    path: path.resolve(__dirname, 'dist')
  },
  devtool: 'inline-source-map',
  plugins: [
    new ExtractTextPlugin("styles.css"),
    new webpack.ProvidePlugin({ // inject ES5 modules as global vars
      $: 'jquery',
      jQuery: 'jquery',
      'window.jQuery': 'jquery',
      Tether: 'tether'
    })
  ],
  module: {
    rules: [
      {
	test: /\.css$/,
	use: ExtractTextPlugin.extract({
	  fallback: 'style-loader',
	  use: 'css-loader'
	})
      },
      {
	test: /\.(png|svg|jpg|gif)$/,
	use: [
	  'file-loader'
	]
      },
      {
	test: /\.(woff|woff2|eot|ttf|otf)$/,
	use: [
	  'file-loader'
	]
      }      
    ]
  }
};