Fix repl does not work with vim-fireplace.

This pull request modifies the project.clj file such that a name-space is created
for each of the koan files.

This change allows vim-fireplace users to be able to use the repl from
the editor, otherwise the repl throws an exception.

Note  that I did try to load this via a `(doseq ...)` form but for whatever reason it does not work doing it that way.