Check out Karabiner and Seil- you can even use these to map "tap capslock" to esc and "hold down capslock" to ctrl. (Seil has some issues in 10.12, but they're working on it.)
They have made karabiner-elements to do just some basic things and which works with sierra. I had a problem with it though as it remaps F-keys by default and it was clashing with Palua on 10.12
