Add CMake example

cmake-example/tests/foo_test.cpp

@@ -0,0 +1,8 @@
+#include "catch.hpp"
+
+#include "mylib/foo.hpp"
+
+TEST_CASE("Foo Test", "[foo]")
+{
+	REQUIRE(mylib::foo() == 42);
+}

cmake-example/tests/test_runner.cpp

@@ -0,0 +1,2 @@
+#define CATCH_CONFIG_MAIN
+#include "catch.hpp"