docs: function prompt (arg, promptStr, defaultValue) {
    if (process.argv.indexOf('--auto') > -1) {
      return Promise.resolve(defaultValue)
    }
    if (process.argv.indexOf('--all') > -1) {
      return Promise.resolve('all')
    }
  
    let idx = process.argv.indexOf(arg)
    if (idx > -1) {
      let val = process.argv[idx + 1]
      if (!val || val.match(/^-+/)) {
        val = defaultValue
      }
      return Promise.resolve(val)
    }
  
    return new Promise((resolve, reject) => {
      process.stdout.write(`${chalk.bold(promptStr)}: [${chalk.gray.underline(defaultValue)}] `)
      process.stdin.resume()
      process.stdin.setEncoding('utf8')
      process.stdin.once('data', val => {
        resolve(val.replace('\n', '') || defaultValue)
        process.stdin.pause()
      })
    })
  }