Update test_fitting_missing_data_units
Update test_fitting_missing_data_units

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