Rolls back clojure version, fixes tests

In updating the mongofinil Clojure version from 1.3 to 1.4, I broke
existing tests. Since I don't really understand why things broke, I'm
rolling the version back to 1.3 and just re-writing the one function I
had that required a version 1.4 function, which frankly makes this more
readable anyways.
Merge pull request #13 from circleci/fix-tests

Rolls back clojure version, fixes tests