security: Move KeyChain to security::v1 namespace and deprecated it

Change-Id: Ic4b6915ca15998a83b410f3f8fac027f797ee7ca
Refs: #3098
diff --git a/tools/ndnsec/unlock-tpm.hpp b/tools/ndnsec/unlock-tpm.hpp
index 2127848..927bc81 100644
--- a/tools/ndnsec/unlock-tpm.hpp
+++ b/tools/ndnsec/unlock-tpm.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2015 Regents of the University of California.
+ * Copyright (c) 2013-2017 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -62,7 +62,7 @@
 
   bool isUnlocked = false;
 
-  KeyChain keyChain;
+  ndn::security::v1::KeyChain keyChain;
 
   char* password;
   password = getpass("Password to unlock the TPM: ");