Add test case BTCChinaGetMarketDepthResponse.
Add date to BTCChinaMarketDepth.
Add adapter methods for adapting BTCChinaMarketDepth to OrderBook.
Merge branch 'develop' of github.com:timmolter/XChange into develop
Add date in adapting BTCChina ticker.
Add date to BTCChinaDepth and use array instead of list to store the ask orders and bid orders.
Use adpatDate in BTCChinaAdapters to make consistent.
Merge pull request #574 from sutra/develop

Add date property to BTCChina market depth, ticker