Add __iter__ to Row per idea from @embray
Add __iter__ to Row per idea from @embray

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