Add test for fftmult shapes
Add test for fftmult shapes

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