manager: Add build testcase

Add a basic compile time test that ensures manager.hpp can build on
its own.

Change-Id: Id10cdd8135fd4a41ebf2a76bc1e0da2d1916c6fa
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/test/manager_test.cpp b/test/manager_test.cpp
new file mode 100644
index 0000000..712e9cf
--- /dev/null
+++ b/test/manager_test.cpp
@@ -0,0 +1 @@
+#include "../manager.hpp"