add another roundtrip test
add another roundtrip test

lpsinger/astropy,mhvk/astropy,saimn/astropy,lpsinger/astropy,astropy/astropy,larrybradley/astropy,saimn/astropy,lpsinger/astropy,astropy/astropy,lpsinger/astropy,pllim/astropy,aleksandr-bakanov/astropy,saimn/astropy,StuartLittlefair/astropy,pllim/astropy,StuartLittlefair/astropy,mhvk/astropy,saimn/astropy,pllim/astropy,larrybradley/astropy,larrybradley/astropy,astropy/astropy,astropy/astropy,StuartLittlefair/astropy,mhvk/astropy,aleksandr-bakanov/astropy,astropy/astropy,StuartLittlefair/astropy,pllim/astropy,mhvk/astropy,saimn/astropy,aleksandr-bakanov/astropy,mhvk/astropy,larrybradley/astropy,StuartLittlefair/astropy,lpsinger/astropy,aleksandr-bakanov/astropy,larrybradley/astropy,pllim/astropy