fix test file

beautiful-racket-demo/jsonic-demo/jsonic-test.rkt

@@ -2,12 +2,10 @@
 // a line comment
 [
   @$ 'null $@,
-    @$ #f $@,
-    @$ #t $@,
   @$ (* 6 7) $@,
-    @$ "string" $@,
+  @$ (= 2 (+ 1 1)) $@,
   @$ (list "array" "of" "strings") $@,
-    @$ (hash 'key-1 42
+  @$ (hash 'key-1 'null
-             'key-2 "value"
+           'key-2 (even? 3)
            'key-3 (hash 'subkey 21)) $@
 ]