Fix extension module namespace.
Fix extension module namespace.

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