Added test for gzip file suggested by Erik Bray.
Added test for gzip file suggested by Erik Bray.

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