code: function log () {
      if (argv.stdin && argv.fix) {
        arguments[0] = opts.cmd + ': ' + arguments[0]
        console.error.apply(console, arguments)
      } else {
        console.log.apply(console, arguments)
      }
    }
docs: Print lint errors to stdout -- this is expected output from `standard-engine`.
  Note: When fixing code from stdin (`standard --stdin --fix`), the transformed
  code is printed to stdout, so print lint errors to stderr in this case.