Bug Fix / Bug 修正

* fixed : not having a unified unit of time, caused heartbeat timeout. see `web-server/public/js/lib/build/build.js` for detail.
  由时间单位不统一而引起的心跳超时. 详见 `web-server/public/js/lib/build/build.js`

* modified : package.json to update the version of dependent packages.
  修改了 package.json, 以更新依赖包的版本.

#### 注意
同时提醒一下, pomelo 主代码中, `pomelolib/connectors/commands/heartbeat.js` Line 12:

    this.hearbeat = null;

拼写错误. 应为:

    this.heartbeat = null;

0.3.4 是错的, MASTER 也还是错的.