MAINT: Use a Series for returns instead of list.
MAINT: Use a Series for returns instead of list.

Make the granularity and range of the returns more explicit.

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