Parameterizes test_tracker test with different days' events dropped.
Parameterizes test_tracker test with different days' events dropped.

So that the test ensures that perf messages are returned when
data is missing from the beginning, middle, and end of data.

magne-max/zipline-ja,ronalcc/zipline,magne-max/zipline-ja,MonoCloud/zipline,CDSFinance/zipline,MonoCloud/zipline,DVegaCapital/zipline,dmitriz/zipline,erikness/AlephOne,keir-rex/zipline,DVegaCapital/zipline,semio/zipline,cmorgan/zipline,dmitriz/zipline,jordancheah/zipline,semio/zipline,Scapogo/zipline,StratsOn/zipline,ChinaQuants/zipline,joequant/zipline,cmorgan/zipline,umuzungu/zipline,alphaBenj/zipline,YuepengGuo/zipline,aajtodd/zipline,kmather73/zipline,jimgoo/zipline-fork,dhruvparamhans/zipline,humdings/zipline,AlirezaShahabi/zipline,bartosh/zipline,wubr2000/zipline,iamkingmaker/zipline,StratsOn/zipline,zhoulingjun/zipline,ronalcc/zipline,CarterBain/AlephNull,morrisonwudi/zipline,CDSFinance/zipline,AlirezaShahabi/zipline,sketchytechky/zipline,nborggren/zipline,davidastephens/zipline,quantopian/zipline,stkubr/zipline,nborggren/zipline,grundgruen/zipline,quantopian/zipline,jimgoo/zipline-fork,CarterBain/AlephNull,dkushner/zipline,kmather73/zipline,ChinaQuants/zipline,florentchandelier/zipline,YuepengGuo/zipline,wilsonkichoi/zipline,enigmampc/catalyst,stkubr/zipline,gwulfs/zipline,jordancheah/zipline,bartosh/zipline,gwulfs/zipline,alphaBenj/zipline,otmaneJai/Zipline,euri10/zipline,erikness/AlephOne,umuzungu/zipline,sketchytechky/zipline,mattcaldwell/zipline,davidastephens/zipline,michaeljohnbennett/zipline,chrjxj/zipline,florentchandelier/zipline,joequant/zipline,humdings/zipline,aajtodd/zipline,enigmampc/catalyst,dkushner/zipline,keir-rex/zipline,dhruvparamhans/zipline,iamkingmaker/zipline,michaeljohnbennett/zipline,chrjxj/zipline,wilsonkichoi/zipline,wubr2000/zipline,grundgruen/zipline,Scapogo/zipline,euri10/zipline,mattcaldwell/zipline,zhoulingjun/zipline,morrisonwudi/zipline,otmaneJai/Zipline