Attempt One at Levenshtein Distance

Greetings !

This is my first attempt at solving the levenshtein distance problem using Clojure. :)

It doesn't cover all use cases:
1) No empty string coverage.
2) The longer string must be first, though I could be mistaken and it's just horribly broken. 

Also let me know if my Git Fu is weak and I should have made a branch.