Fix missing #include

Change-Id: If00c50a2ed2df103587ff27e285c4348e7600add
diff --git a/y2014/hot_goal_reader.cc b/y2014/hot_goal_reader.cc
index 7bf9fa2..0b24f22 100644
--- a/y2014/hot_goal_reader.cc
+++ b/y2014/hot_goal_reader.cc
@@ -4,6 +4,7 @@
 #include <string.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#include <unistd.h>
 
 #include "aos/common/time.h"
 #include "aos/common/logging/queue_logging.h"