Fix compilation with Boost 1.65.0

Change-Id: I6f56d6bf135d9c862b04cb086340301ee98ef0ed
Refs: #4256
diff --git a/tests/integrated/encoding-benchmark.cpp b/tests/integrated/encoding-benchmark.cpp
index bd24f77..d18fa29 100644
--- a/tests/integrated/encoding-benchmark.cpp
+++ b/tests/integrated/encoding-benchmark.cpp
@@ -27,9 +27,12 @@
 
 #include "boost-test.hpp"
 #include "timed-execute.hpp"
+
 #include <boost/mpl/vector.hpp>
 #include <boost/mpl/vector_c.hpp>
 
+#include <iostream>
+
 namespace ndn {
 namespace tlv {
 namespace tests {
diff --git a/tests/integrated/scheduler-benchmark.cpp b/tests/integrated/scheduler-benchmark.cpp
index 3074d22..5fa57b7 100644
--- a/tests/integrated/scheduler-benchmark.cpp
+++ b/tests/integrated/scheduler-benchmark.cpp
@@ -28,6 +28,8 @@
 #include "boost-test.hpp"
 #include "timed-execute.hpp"
 
+#include <iostream>
+
 namespace ndn {
 namespace util {
 namespace scheduler {