STY PEP8 fix.
STY PEP8 fix.

dursk/pyfolio,femtotrader/pyfolio,raybuhr/pyfolio,sketchytechky/pyfolio,r0k3/pyfolio,YihaoLu/pyfolio,chayapan/pyfolio,YihaoLu/pyfolio,yanheven/pyfolio,ChinaQuants/pyfolio,raybuhr/pyfolio,ChinaQuants/pyfolio,femtotrader/pyfolio,quantopian/pyfolio,sketchytechky/pyfolio,dursk/pyfolio,yanheven/pyfolio,quantopian/pyfolio,r0k3/pyfolio