fix: rename test module to tests

examples/acceptance_tests/024/lib/tests.ak

@@ -0,0 +1,18 @@
+pub fn map2(
+  opt_a: Option<a>,
+  opt_b: Option<b>,
+  f: fn(a, b) -> result,
+) -> Option<result> {
+  when opt_a is {
+    None -> None
+    Some(a) ->
+      when opt_b is {
+        None -> None
+        Some(b) -> Some(f(a, b))
+      }
+  }
+}
+
+test map2_3() {
+  map2(Some(14), Some(42), fn(a, b) { #(a, b) }) == Some(#(14, 42))
+}