Update dataService.py
Update dataService.py

修改bar.date为date，而非原来的trade_date。
bigdig/vnpy,msincenselee/vnpy,andrewchenshx/vnpy,msincenselee/vnpy,wisfern/vnpy,wisfern/vnpy,harveywwu/vnpy,wisfern/vnpy,rrrrrr8/vnpy,andrewchenshx/vnpy,andrewchenshx/vnpy,bigdig/vnpy,rrrrrr8/vnpy,rrrrrr8/vnpy,harveywwu/vnpy,vnpy/vnpy,msincenselee/vnpy,bigdig/vnpy,andrewchenshx/vnpy,harveywwu/vnpy,harveywwu/vnpy,wisfern/vnpy,harveywwu/vnpy,msincenselee/vnpy,rrrrrr8/vnpy,andrewchenshx/vnpy,bigdig/vnpy,rrrrrr8/vnpy,vnpy/vnpy,wisfern/vnpy,wisfern/vnpy,harveywwu/vnpy,rrrrrr8/vnpy