all: Update code to compile with latest time-related changes in ndn-cpp-dev library

Change-Id: I7e859989c833001f49b286d4a9917f4dc740b4a4
diff --git a/tests/mgmt/command-validator.cpp b/tests/mgmt/command-validator.cpp
index 3dcae24..e2cf51c 100644
--- a/tests/mgmt/command-validator.cpp
+++ b/tests/mgmt/command-validator.cpp
@@ -84,7 +84,7 @@
   generateIdentity(const Name& prefix)
   {
     m_identityName = prefix;
-    m_identityName.append(boost::lexical_cast<std::string>(ndn::time::now()));
+    m_identityName.appendVersion();
 
     const Name certName = m_keys.createIdentity(m_identityName);