webpack.config.dev.js

    entry: {
        app: [
            'webpack-dev-server/client?http://localhost:8080',
            'webpack/hot/only-dev-server',
            './app/main.js'
        ],
        vendor: './app/vendor/vendor.js',
        editor: './app/vendor/editor.js'
    },
...
    plugins: [
        new webpack.optimize.CommonsChunkPlugin({
            name: [ 'vendor', 'editor' ],
            filename: '[name].js',
            minChunks: Infinity
        }),