Alphabet Cipher kata

For this first 2016 meeting, we'll do some hands-on coding doing the Alphabet Cipher kata (https://github.com/gigasquid/wonderland-clojure-katas/tree/master/alphabet-cipher) from Carin Meier (http://gigasquidsoftware.com/)'s Living Clojure (http://shop.oreilly.com/product/0636920034292.do) Training Program.