Remove name-spaces from koans on slurp.

There a couple of proposals at the functional-koans/clojure-koans that
will add a name-space to the koans files in order to fix an issue
related to the REPL.

If one of these pull request is merged in, then a change like this one
will be needed in order to maintain a pass on `lein koan test`.
Merge pull request #9 from dkinzer/remove-namespaces

Remove name-spaces from koans on slurp.