add action and reducer for transaction/stock/ballance

[xxxxjunwu]

There are still some unsolved yet (only prototype..).. As I am not sure where to get the data since we only have Tick model and not sure what kind of data will the model store / return.

Action:

1. stockAction.js
   1. POJO action :
      1. buyStock(stock) :
      2. sellStock(stock)
   2. Middleware:
      1. buyingStock(userID, stockID, number)
      2. sellingStock(userID, stockID, number)
2. ballanceAction.js
   1. POJO action:
      1. receiveBallance(ballance)
   2. MiddleWare:
      1. fetchBallance(userID)
3. transactionAction.js
   1. POJO action:
      1. receveTransaction(transaction)
   2. MiddleWare:
      1. fetchTransaction(userID)

Reducer:

1. stockReducer.js
   1. Case: BUY_STOCK, SELL_STOCK
2. ballanceReducer.js
   1. case: RECEIVE_BALLANCE
3. transactionReducer.js
   1. Case: RECEIVE_TRANSACTION