Feat: support shell script

[imcuttle]

• Expected

cli()
  .use('echo foo | cat')
  .end(function(err, stdout, stderr) {
     console.log(stdout)
     if (err) throw err
  })

// Log:  
// { status: 0, text: 'foo', err: null } undefined

• Actual

cli()
  .use('echo foo | cat')
  .end(function(err, stdout, stderr) {
     console.log(stdout)
     if (err) throw err
  })

// Log:  
// { status: 0, text: '123 | cat\n', err: null } undefined

[mklabs]

Hi @imcuttle

What is the issue exactly ? I didn't use gentle-cli in a while. It's probably because you pipe cat. I admit I didn't use or tested this use case.

It seems a valid issue.