message: build: exit when given bad args
diff: @@ -20,6 +20,7 @@ for (let i = 2; i < process.argv.length; i++) {
  default:
  console.error('error: unexpected argument:', process.argv[i]);
  console.error('update-website [--no-commit|--force]');
  + process.exit(-1);
  }
  }
  