Added zip, neighbors?, and tests.
Add initial-wordlist and tests.
Modified neighbors? function.
Add remember, remove-word, and tests.
Skeleton of a solution.
Add find-neighbors.
Add Midje.
Migrate tests to Midje.
Progress towards a solution.
A solution! Huzzah!
Some refactoring.

This solution is probably a bit more verbose, but I like it better.
Refactor words.
Call remove-word rember.
More efficient "leaves" function.

And documentation.
Refactor wordlist.