docs: function spawn(command, args, cb) {
  
    var _spawn = child.spawn(command, args);
  
    _spawn.stdout.on('data', function (data) {
      process.stdout.write(colors.green(data.toString()));
    });
  
    _spawn.stderr.on('data', function (data) {
      process.stderr.write(colors.red(data.toString()));
    });
  
    _spawn.on('exit', function (code) {
      cb((code !== 0) ? new Error(code) : undefined, code);
    });
  }