Make ordered_pip.sh more robust
Make ordered_pip.sh more robust

Make ordered_pip.sh exit on error. Remove useless echo of empty
string. Fix counting of the number of packages installed. Ignore blank
lines in requirements file.

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