Adjust includes for the updated locations of ndn-cxx security headers

Change-Id: Id1e44e929541fdd1132a4b3e6366404232351e68
diff --git a/tests/test-common.hpp b/tests/test-common.hpp
index 6553b7f..0746b83 100644
--- a/tests/test-common.hpp
+++ b/tests/test-common.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2017, Regents of the University of California.
+ * Copyright (c) 2014-2020, Regents of the University of California.
  *
  * This file is part of NDNS (Named Data Networking Domain Name Service).
  * See AUTHORS.md for complete list of NDNS authors and contributors.
@@ -43,10 +43,10 @@
 namespace ndns {
 namespace tests {
 
-using ndn::security::v2::KeyChain;
+using ndn::security::KeyChain;
 using ndn::security::Identity;
 using ndn::security::pib::Key;
-using ndn::security::v2::Certificate;
+using ndn::security::Certificate;
 
 /** \brief create an Interest
  *  \param name Interest name