strategy:turtle/turt1: use ATR as minPosIntv

1) Add support to use ATR as minPosIntv for turt1 strategy.
2) Add checkAtr() and getAtr() for TurtData.
3) Update regression framework to be able to use ATR as
   minPosIntv.

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