Add userlib tests

Document userlib in readme
extend example configuration to include userlib

snippets/userlib-tests.rls

@@ -0,0 +1,43 @@
+;; this file implements unit tests for handwritten userlib functions
+
+(def passed
+'prints if a test has passed'
+  (test)
+  (echo (concat "PASSED: " test)))
+
+(def failed
+'prints if a test has failed'
+  (test)
+  (echo (concat "FAILED: " test)))
+  
+(def test-cases 'all test cases'
+  (('set updates var'
+     (quote
+       (let ((test-val 0))
+         (set test-val 3)
+         (eq? test-val 3))))
+   ('prepend prepends to list'
+     (quote
+       (let ((list (2 3 4))
+             (list (prepend 1 list))
+             (list-head (head list)))
+         (eq? (car list-head) 1))))
+
+     ;; add more test cases here
+   ))
+
+
+(def test-iter 'iterates over test cases'
+  (head test-cases))
+
+;; run all test cases, print output
+(while (gt? (len (cdr test-iter))
+         0)
+  (let ((test (car test-iter))
+        (remaining (cdr test-iter))
+        (test-name (car test))
+        (test-body (cdr test)))
+  (if (eval test-body)
+    (passed test-name)
+    (failed test-name))
+  (def test-iter '' (head remaining))))