Automatically link Ruby installs to readline

Formula was removed
Last version was:
1.0.0 HEAD

Homepage: https://github.com/tpope/rbenv-readline

Formula history

ilovezfs rbenv-readline: migrate to boneyard (#4974)
Dominyk Tiller rbenv-readline: use assert_match in test
Dominyk Tiller rbenv-readline: use new rbenv dependency
Mike McQuaid rbenv-readline: bottle unneeded
Nikolaus Wittenstein Add descriptions to all remaining homebrew packages
Xu Cheng modernize and add test for rbenv and its family
Mike McQuaid rbenv-readline 1.0.0 (new formula)