Update `brew ls` to work when the cellar doesn't exist
Update `brew ls` to work when the cellar doesn't exist

nandub/brew,JCount/brew,MikeMcQuaid/brew,MikeMcQuaid/brew,MikeMcQuaid/brew,Homebrew/brew,MikeMcQuaid/brew,nandub/brew,Homebrew/brew,JCount/brew,Homebrew/brew,nandub/brew,JCount/brew,nandub/brew,Homebrew/brew,JCount/brew