minor docstring improvment
minor docstring improvment

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