rgb2grey -> grey2rgb
rgb2grey -> grey2rgb

Simply added `grey2rgb = gray2rgb` to match the existing rgb2grey.
rjeli/scikit-image,ajaybhat/scikit-image,paalge/scikit-image,ofgulban/scikit-image,vighneshbirodkar/scikit-image,pratapvardhan/scikit-image,ofgulban/scikit-image,vighneshbirodkar/scikit-image,Hiyorimi/scikit-image,ajaybhat/scikit-image,rjeli/scikit-image,rjeli/scikit-image,pratapvardhan/scikit-image,ofgulban/scikit-image,vighneshbirodkar/scikit-image,Hiyorimi/scikit-image,paalge/scikit-image,paalge/scikit-image