small docstring fixes in setup_helpers
small docstring fixes in setup_helpers

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