Fix doctest that was failing on Python 2 due to assumption of using the print() function.
Fix doctest that was failing on Python 2 due to assumption of using the print() function.

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