PEP8 changes for core.py
PEP8 changes for core.py

funbaker/astropy,StuartLittlefair/astropy,kelle/astropy,tbabej/astropy,DougBurke/astropy,bsipocz/astropy,larrybradley/astropy,astropy/astropy,saimn/astropy,lpsinger/astropy,mhvk/astropy,pllim/astropy,astropy/astropy,aleksandr-bakanov/astropy,funbaker/astropy,StuartLittlefair/astropy,MSeifert04/astropy,stargaser/astropy,lpsinger/astropy,aleksandr-bakanov/astropy,dhomeier/astropy,larrybradley/astropy,AustereCuriosity/astropy,stargaser/astropy,funbaker/astropy,tbabej/astropy,stargaser/astropy,saimn/astropy,DougBurke/astropy,dhomeier/astropy,aleksandr-bakanov/astropy,stargaser/astropy,astropy/astropy,saimn/astropy,mhvk/astropy,pllim/astropy,AustereCuriosity/astropy,astropy/astropy,AustereCuriosity/astropy,pllim/astropy,AustereCuriosity/astropy,dhomeier/astropy,tbabej/astropy,pllim/astropy,astropy/astropy,MSeifert04/astropy,joergdietrich/astropy,pllim/astropy,bsipocz/astropy,StuartLittlefair/astropy,dhomeier/astropy,joergdietrich/astropy,joergdietrich/astropy,DougBurke/astropy,mhvk/astropy,larrybradley/astropy,joergdietrich/astropy,larrybradley/astropy,AustereCuriosity/astropy,StuartLittlefair/astropy,tbabej/astropy,aleksandr-bakanov/astropy,saimn/astropy,StuartLittlefair/astropy,mhvk/astropy,lpsinger/astropy,MSeifert04/astropy,MSeifert04/astropy,funbaker/astropy,saimn/astropy,kelle/astropy,DougBurke/astropy,kelle/astropy,larrybradley/astropy,joergdietrich/astropy,bsipocz/astropy,bsipocz/astropy,lpsinger/astropy,tbabej/astropy,lpsinger/astropy,dhomeier/astropy,mhvk/astropy,kelle/astropy,kelle/astropy