Kata: Numbers Spelling in Clojure

I've just done the Numbers Spelling kata in Clojure:

These are the tests using Midje:

and this is the code:

To document the TDD process I commited the code after every passing test and every refactor. You can find the commits step by step here.

If you look at the commits, you'll notice that it took me some time to find a simple algorithm using TDD but once I found it I could simplify the code quite a bit.

You can find the code in this repository in GitHub.