Remove reference to is_dimensionless in is_unity docstring
Remove reference to is_dimensionless in is_unity docstring

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