ctp:ctpapi/testctp: update

1) Add CtpTraderApi Class.
2) Add test to CtpTraderApi.

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>
ctp:ctpapi: Add settlements related functions

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>
ctp:ctpapi: add functions to trade

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>