Add to Stackage

[pepeiborra]

A useful package - have you considered adding it to Stackage? It's pretty simple - the steps are described at https://github.com/fpco/stackage/blob/master/MAINTAINERS.md. Concretely it would make my life easier when I use Hoed, which builds on RBTree, as then I would be able to source it directly from Stackage.