I met a problem when running the demo ding-dong bot on my mac.
Here is the console log

✘ programath@wentuopudeMaxBook-Air ⮀ ~/wechaty ⮀ ⭠ master ● ⮀ node example/ding-dong-bot.js

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=============== Powered by Wechaty ===============
-------- https://github.com/zixia/wechaty --------

I'm a bot, my super power is talk in Wechat.

If you send me a 'ding', I will reply you a 'dong'!

Hope you like it, and you are very welcome to
upgrade me for more super powers!

Please wait... I'm trying to login in...

info Wechaty v0.3.9 initializing...
undefined
WARN PuppetWebBridge init() inject FINAL fail: execute proxyWechaty(init) error: 503, init() without a ready angular env
ERR! PuppetWeb initBridge() exception: execute proxyWechaty(init) error: 503, init() without a ready angular env
ERR! PuppetWeb init exception: execute proxyWechaty(init) error: 503, init() without a ready angular env
ERR! Wechaty init() exception: execute proxyWechaty(init) error: 503, init() without a ready angular env
ERR! Bot Error: execute proxyWechaty(init) error: 503, init() without a ready angular env
ERR! Bot at Bridge. (/Users/programath/wechaty/src/puppet-web/bridge.js:84:15)
ERR! Bot at next (native)
ERR! Bot at onFulfilled (/Users/programath/wechaty/node_modules/co/index.js:65:19)
ERR! Bot at ManagedPromise.invokeCallback_ (/Users/programath/wechaty/node_modules/selenium-webdriver/lib/promise.js:1315:14)
ERR! Bot at TaskQueue.execute_ (/Users/programath/wechaty/node_modules/selenium-webdriver/lib/promise.js:2736:14)
ERR! Bot at TaskQueue.executeNext_ (/Users/programath/wechaty/node_modules/selenium-webdriver/lib/promise.js:2719:21)
ERR! Bot at asyncRun (/Users/programath/wechaty/node_modules/selenium-webdriver/lib/promise.js:2595:27)
ERR! Bot at /Users/programath/wechaty/node_modules/selenium-webdriver/lib/promise.js:639:7
ERR! Bot at process.tickCallback (internal/process/next_tick.js:103:7)
ERR! Bot init() fail: %s Error: execute proxyWechaty(init) error: 503, init() without a ready angular env
ERR! Bot at Bridge. (/Users/programath/wechaty/src/puppet-web/bridge.js:84:15)
ERR! Bot at next (native)
ERR! Bot at onFulfilled (/Users/programath/wechaty/node_modules/co/index.js:65:19)
ERR! Bot at ManagedPromise.invokeCallback (/Users/programath/wechaty/node_modules/selenium-webdriver/lib/promise.js:1315:14)
ERR! Bot at TaskQueue.execute_ (/Users/programath/wechaty/node_modules/selenium-webdriver/lib/promise.js:2736:14)
ERR! Bot at TaskQueue.executeNext_ (/Users/programath/wechaty/node_modules/selenium-webdriver/lib/promise.js:2719:21)
ERR! Bot at asyncRun (/Users/programath/wechaty/node_modules/selenium-webdriver/lib/promise.js:2595:27)
ERR! Bot at /Users/programath/wechaty/node_modules/selenium-webdriver/lib/promise.js:639:7
ERR! Bot at process._tickCallback (internal/process/next_tick.js:103:7)

The version of node is v6.4.0 and npm is 3.10.3
Can you tell me what's going wrong?