Scheduler

It's a half done pull request, need some feedback to improvement the code. It's aim to schedule the user configured task resource requests.
Mainly done: 
1. move the package into cluster
2. package workerInfo( Todo: using host:port)
3. parse the configuration into task arrangement


I remembered that we discussed this. 

After allocation, we need to update the resources, and add a timeout to recover the resource available if the worker don't report-in in time.