code: function parseLogLevel (logLevel) {
    if (!/debug|info|warn|error|off/i.test(logLevel)) {
      console.error('Log level must be one of the following (debug|info|warn|error|off)')
      process.exit(1)
    }
    return logLevel.toUpperCase()
  }
docs: Used by commander to parse the log level and fails if invalid
  value is passed in
  @private