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Based on
http://about.travis-ci.org/docs/user/status-images/#Status-Image-URLs,
which says that github doesn't cache https requests.

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