Update astropy-helpers instructions for new procedure
Update astropy-helpers instructions for new procedure

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