Fixes eidheim#103: added missing include

eidheim · eidheim · commit 13418d1b4d54 · 2018-07-23T21:34:31.000+02:00
diff --git a/utility.hpp b/utility.hpp
@@ -3,6 +3,7 @@
 
 #include "status_code.hpp"
 #include <atomic>
+#include <cstdlib>
 #include <iostream>
 #include <memory>
 #include <string>
