Move changelog entry to 3.1 [ci skip]
Move changelog entry to 3.1 [ci skip]

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