message: simplify rollup config
diff: @@ -6,14 +6,7 @@ const formats = ['esm', 'umd'] // 'cjs' ?
  export default {
  input: 'src/index.js',
  plugins: [
  - babel({
  - babelrc: false,
  - exclude: 'node_modules/**',
  - plugins: [
  - 'external-helpers'
  - ],
  - presets: ['next/babel']
  - }),
  + babel({exclude: 'node_modules/**'}),
  commonjs()
  ],
  output: formats.map(format => ({
  