webpack.config.js

module.exports = {
  entry: './src/js/index.js',
  output: {
    filename: './dist/js/index.js'       
  },
  module: {
    loaders: [{
      loader: 'babel',
      exclude: /node_modules/,
      include: '/src/', //include should be in array
      test: /\.js$/,
      query: {
        presets: ['es2015', 'stage-0', 'react']
      }
    }]
  }
};