Fixed test dir.

test/tests.c

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) 2021 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "poker/card.h"
+#include "poker/poker.h"
+
+int main() {
+  return (
+    !test_card() &&
+    !test_poker2()
+  );
+}