added changelog entry for #498
added changelog entry for #498

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