now, the all above modules have the same targetState() & currentState() code, should be modulized & well tested, to make sure all the state are well monitor & managed.

• Browser Class
• [ ] Bridge Class
• [ ] Server Class
• Puppet Class
• Wechaty Class
• Io Class
• IoClient Class

StateMonitor Class: https://github.com/wechaty/wechaty/blob/master/src/state-monitor.ts

after this, Watchdog should work better, and we can dig deeper for how to deal with browser problems, i.e.: killed by operation system or hang with no reason.