fix: rename test module to tests

examples/acceptance_tests/014/lib/tests.ak

@@ -0,0 +1,7 @@
+// NOTE:
+// Somehow, the left-hand evaluates to: [#00, #20, #21]
+// whereas the right-hand evaluates to: [#21, #20, #00]
+//
+test foo() {
+  [0 - 2, 0 - 1, 0] == [-2, -1, 0]
+}