added more test cases
added more test cases

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