STY PEP8 fixes.
STY PEP8 fixes.

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