allow multi entry

[Jetsly]

i have muti entry,but output is specified arguments,so i add a placeholder

gulp.task('start', () => {
  return gulp.src(`./src/js/*.js`)
    .pipe(rollup({
      format: 'umd',
      plugins: [
        vue(),
        scss({
          output: "dist/[name].css"
        })
      ]
    }))
    .pipe(gulp.dest('./dist'));
});

[Jetsly]

then styles obj is single ,so need

 // Emit styles to file
fs.writeFile(destPath, css, function (err) {
   if (err) {
    throw err
  }
  console.log(green(destPath), getSize(css.length));
  styles={} //need to clear 
});

[Jetsly]

i think is not good idea