add simple unittest

test/test_runner.cpp

@@ -0,0 +1,14 @@
+/*
+ *  test_runner.cpp
+ *  Author: Benjamin Sergeant
+ *  Copyright (c) 2018 Machine Zone. All rights reserved.
+ */
+
+#define CATCH_CONFIG_RUNNER
+#include "catch.hpp"
+
+int main(int argc, char* argv[]) 
+{
+    int result = Catch::Session().run(argc, argv);
+    return result;
+}