update header files in tests

Change-Id: Ibfffb9367349f58eeb193350bad34fdfccd8c553
diff --git a/tests/unit-tests/bench.t.cpp b/tests/unit-tests/bench.t.cpp
index 038e97b..46b56ef 100644
--- a/tests/unit-tests/bench.t.cpp
+++ b/tests/unit-tests/bench.t.cpp
@@ -19,17 +19,10 @@
  */
 
 #include "ca-module.hpp"
-#include "identity-management-fixture.hpp"
 #include "client-module.hpp"
 #include "challenge-module/challenge-pin.hpp"
 #include "protocol-detail/info.hpp"
-
-#include <ndn-cxx/util/dummy-client-face.hpp>
-#include <ndn-cxx/security/signing-helpers.hpp>
-#include <ndn-cxx/security/transform/public-key.hpp>
-#include <ndn-cxx/security/verification-helpers.hpp>
-#include <ndn-cxx/metadata-object.hpp>
-#include <iostream>
+#include "test-common.hpp"
 
 namespace ndn {
 namespace ndncert {