Use clojure.test framework instead of asserts so all of the tests are consistent.

Only a few tests were using assert, so converted them to use clojure.test. Also fix the kindergarten-garden example so that it passed the tests.
Merge pull request #1180 from geofflane/clojure_use_clojure.test

Use clojure.test framework instead of asserts so all of the tests are consistent.