I don't have my Mac in front of me, but you can do this using Seil[1] and Karabiner[2]. From recollection, you disable caps-link in OS X settings, use Seil to map caps-lock to control, and then use Karabiner to map tapped-ctrl to escape. Sounds a bit hackish, but it works very well.

You can also do the same thing on Linux using xcape[3]

[1]: https://pqrs.org/osx/karabiner/seil.html.en [2]: https://pqrs.org/osx/karabiner/index.html.en [3]: https://github.com/alols/xcape