Fix ASDF tag test helper to load schemas correctly
Fix ASDF tag test helper to load schemas correctly

larrybradley/astropy,larrybradley/astropy,mhvk/astropy,MSeifert04/astropy,bsipocz/astropy,mhvk/astropy,saimn/astropy,pllim/astropy,stargaser/astropy,stargaser/astropy,lpsinger/astropy,StuartLittlefair/astropy,mhvk/astropy,dhomeier/astropy,saimn/astropy,stargaser/astropy,stargaser/astropy,dhomeier/astropy,pllim/astropy,bsipocz/astropy,lpsinger/astropy,dhomeier/astropy,saimn/astropy,StuartLittlefair/astropy,dhomeier/astropy,aleksandr-bakanov/astropy,larrybradley/astropy,saimn/astropy,astropy/astropy,StuartLittlefair/astropy,astropy/astropy,aleksandr-bakanov/astropy,lpsinger/astropy,StuartLittlefair/astropy,dhomeier/astropy,MSeifert04/astropy,saimn/astropy,bsipocz/astropy,astropy/astropy,astropy/astropy,bsipocz/astropy,MSeifert04/astropy,pllim/astropy,MSeifert04/astropy,astropy/astropy,StuartLittlefair/astropy,aleksandr-bakanov/astropy,lpsinger/astropy,mhvk/astropy,larrybradley/astropy,lpsinger/astropy,aleksandr-bakanov/astropy,mhvk/astropy,larrybradley/astropy,pllim/astropy,pllim/astropy