code: function exec(command, options) {
      var d = Promise.defer();
  
      var child = childProcess.exec(command, options, function(err, stdout, stderr) {
          if (!err) {
              return d.resolve();
          }
  
          err.message = stdout.toString('utf8') + stderr.toString('utf8');
          d.reject(err);
      });
  
      child.stdout.on('data', function (data) {
          d.notify(data);
      });
  
      child.stderr.on('data', function (data) {
          d.notify(data);
      });
  
      return d.promise;
  }
docs: Execute a command
  
  @param {String} command
  @param {Object} options
  @return {Promise}