Squashed 'third_party/optional/' content from commit 1baad184f

Change-Id: I9b2473a84dcf6d9892f1f7a9fd21b340796b6ff5
git-subtree-dir: third_party/optional
git-subtree-split: 1baad184f022a3a7502db094a984a86adedf9626
diff --git a/tests/main.cpp b/tests/main.cpp
new file mode 100644
index 0000000..0c7c351
--- /dev/null
+++ b/tests/main.cpp
@@ -0,0 +1,2 @@
+#define CATCH_CONFIG_MAIN
+#include "catch.hpp"