install_helpers: add iostream include to tools

fixes compilation error on Ubuntu 18.04

Change-Id: I5227413788b9a5e1e88c195a20177939fae39281
diff --git a/install_helpers/tools/test-congestionmark-consumer.cpp b/install_helpers/tools/test-congestionmark-consumer.cpp
index fb78312..600133d 100644
--- a/install_helpers/tools/test-congestionmark-consumer.cpp
+++ b/install_helpers/tools/test-congestionmark-consumer.cpp
@@ -14,6 +14,8 @@
 #include <ndn-cxx/interest.hpp>
 #include <ndn-cxx/lp/nack.hpp>
 
+#include <iostream>
+
 using namespace ndn;
 
 class TestCongestionMarkConsumer
diff --git a/install_helpers/tools/test-congestionmark-producer.cpp b/install_helpers/tools/test-congestionmark-producer.cpp
index c83d15d..9d9232e 100644
--- a/install_helpers/tools/test-congestionmark-producer.cpp
+++ b/install_helpers/tools/test-congestionmark-producer.cpp
@@ -15,6 +15,8 @@
 #include <ndn-cxx/lp/tags.hpp>
 #include <ndn-cxx/security/key-chain.hpp>
 
+#include <iostream>
+
 using namespace ndn;
 
 class TestCongestionMarkProducer
diff --git a/install_helpers/tools/test-nack-consumer.cpp b/install_helpers/tools/test-nack-consumer.cpp
index fb6cb96..4af568e 100644
--- a/install_helpers/tools/test-nack-consumer.cpp
+++ b/install_helpers/tools/test-nack-consumer.cpp
@@ -9,6 +9,8 @@
 #include <boost/asio.hpp>
 #include <ndn-cxx/face.hpp>
 
+#include <iostream>
+
 namespace ndn {
 
 class TestNackConsumer : boost::noncopyable
@@ -222,4 +224,4 @@
   testNackConsumer.run();
 
   return 0;
-}
\ No newline at end of file
+}
diff --git a/install_helpers/tools/test-nexthopfaceid-consumer.cpp b/install_helpers/tools/test-nexthopfaceid-consumer.cpp
index 7f5ade4..36f4b6b 100644
--- a/install_helpers/tools/test-nexthopfaceid-consumer.cpp
+++ b/install_helpers/tools/test-nexthopfaceid-consumer.cpp
@@ -1,7 +1,7 @@
 /**
  * Consumer for the NextHopFaceId test (test_nexthopfaceid)
  *
- * Author: Eric Newberry <enewberry@email.arizona.edu>
+ * Author: Eric Newberry <enewberry@cs.arizona.edu>
  *
  * Based on ndn-cxx example consumer
  */
@@ -13,6 +13,7 @@
 
 #include <cstring>
 #include <cstdlib>
+#include <iostream>
 
 using namespace ndn;