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

Change-Id: Ic4b6915ca15998a83b410f3f8fac027f797ee7ca
Refs: #3098
diff --git a/tools/ndnsec/dsk-gen.hpp b/tools/ndnsec/dsk-gen.hpp
index 4f994c3..207100e 100644
--- a/tools/ndnsec/dsk-gen.hpp
+++ b/tools/ndnsec/dsk-gen.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2016 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).
  *
@@ -77,7 +77,7 @@
   shared_ptr<v1::IdentityCertificate> kskCert;
   Name signingCertName;
 
-  KeyChain keyChain;
+  ndn::security::v1::KeyChain keyChain;
 
   try {
     Name defaultCertName = keyChain.getDefaultCertificateNameForIdentity(identityName);