.babelrc

{
    "presets": [
        [
            "env", {
                "targets": {
                    "browsers": ["last 2 versions", "safari >= 7"]
                },
                "modules": false,
                "loose": true
            }
        ],
        "react"
    ],
    "plugins": [
		"transform-class-properties",
		"transform-object-rest-spread"
    ]
}

webpack.config.js

const path = require('path');
const ShakePlugin = require('webpack-common-shake').Plugin;

module.exports = {
	context: path.resolve(__dirname, 'src'),
	entry: {
		main: './index.js',
	},
	output: {
		path: path.resolve(__dirname, 'dist'),
		filename: 'index.js',
		publicPath: 'dist/',
	},
	module: {
		rules: [
			{
				test: /.jsx?$/,
				loader: 'babel-loader',
				exclude: /node_modules/,
			},
			{
				test: /.css?$/,
				loader: ['style-loader', 'css-loader'],
				exclude: /node_modules/,
			},
		],
	},
	plugins: [
		new ShakePlugin()
	],
};