Fixed missing include for V1 `Resources.cpp`.
diff --git a/src/v1/resources.cpp b/src/v1/resources.cpp
index 969c0a6..be4a5d1 100644
--- a/src/v1/resources.cpp
+++ b/src/v1/resources.cpp
@@ -25,6 +25,8 @@
 
 #include <google/protobuf/repeated_field.h>
 
+#include <mesos/roles.hpp>
+
 #include <mesos/v1/mesos.hpp>
 #include <mesos/v1/resources.hpp>
 #include <mesos/v1/values.hpp>