Add tests of pandas backend
Add tests of pandas backend

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