text: // rollup.config.js
  import resolve from 'rollup-plugin-node-resolve';
  import babel from 'rollup-plugin-babel';
  import jsx from 'rollup-plugin-jsx'
  export default {
    entry: 'src/Button.js',
    format: 'cjs',
    plugins: [
      resolve(),
      jsx( {factory: 'React.createElement'} ),
      babel({
        exclude: 'node_modules/**' // only transpile our source code
      })
    ],
    dest: './main.js'
  };
  