webpack.config.js

const path = require('path'),
    webpack = require('webpack'),
    ExtractTextPlugin = require('extract-text-webpack-plugin');

module.exports = {
    context: path.resolve(__dirname, 'src'),
    entry: './index.js',
    output: {
        path: path.resolve(__dirname, 'dist/'),
        filename: 'index.js'
    },
    module: {
        rules: [
            {
                test: /\.js$/,
                use: 'babel-loader'
            },
            {
                test: /\.scss$/,
                use: ExtractTextPlugin.extract({
                    fallback: 'style-loader',
                    use: [
                        'raw-loader',
                        'sass-loader'
                    ]
                })
            }
        ]
    },
    plugins: [
        new ExtractTextPlugin('styles.css')
    ],
    externals: {
        react: 'React'
    }
};