I have been using shelljs

On my super fast system I execute this:

```
var shell = require('shelljs')
const exec = require('child_process').exec

console.time('shell mktemp -d')
shell.exec('mktemp -d', {silent: true})
console.timeEnd('shell mktemp -d')

console.time('child exec mktemp -d')
exec('mktemp', ['-d'], function(error, stdout, stderr) {
  if (error) {
    console.error('stderr', stderr)
    throw error
  }
  console.log('exec stdout', stdout)
  console.timeEnd('child exec mktemp -d')
})

```

Its giving the following execution times:

> 
> shell mktemp -d: 208.126ms
> 
> 
> exec stdout /tmp/tmp.w22tyS5Uyu
> 
> 
> child exec mktemp -d: 48.812ms
> 
> 
> 

Why is shelljs 4 times slower? Any thoughts?