webpack.js

module.exports = {
  entry: "./public/main.js",
  output: {
    filename: "public/bundle.js"
  },
  module: {
    loaders: [
      {
        test: /\.js?$/,
        exclude: /(node_modules|bower_components)/,
        loader: 'babel-loader',
        query: {
          presets: ['react', 'es2015']
        }
      }
    ]
  }
};