Added regression test for ignored in compound bounding box.
Added regression test for ignored in compound bounding box.

astropy/astropy,astropy/astropy,lpsinger/astropy,pllim/astropy,StuartLittlefair/astropy,astropy/astropy,larrybradley/astropy,larrybradley/astropy,astropy/astropy,lpsinger/astropy,larrybradley/astropy,lpsinger/astropy,lpsinger/astropy,pllim/astropy,mhvk/astropy,saimn/astropy,StuartLittlefair/astropy,saimn/astropy,pllim/astropy,saimn/astropy,larrybradley/astropy,lpsinger/astropy,astropy/astropy,mhvk/astropy,StuartLittlefair/astropy,mhvk/astropy,saimn/astropy,mhvk/astropy,larrybradley/astropy,mhvk/astropy,StuartLittlefair/astropy,pllim/astropy,pllim/astropy,StuartLittlefair/astropy,saimn/astropy