Change log entry for new grow parameter of SigmaClip et al.
Change log entry for new grow parameter of SigmaClip et al.

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