Fix bug in show_in_notebook, not supporting mixin columns
Fix bug in show_in_notebook, not supporting mixin columns

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