add missing includes, cleanup

Change-Id: Ifea313cc529a6c21c040b99748b2b5f502d021fe
diff --git a/include/ice_transport.h b/include/ice_transport.h
index 8fc447d..7403e99 100644
--- a/include/ice_transport.h
+++ b/include/ice_transport.h
@@ -23,10 +23,12 @@
 #include "ice_options.h"
 #include "ip_utils.h"
 
+#include <msgpack.hpp>
+
 #include <functional>
 #include <memory>
-#include <msgpack.hpp>
 #include <vector>
+#include <chrono>
 
 extern "C" {
 struct pj_ice_sess_cand;