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

Change-Id: Ic4b6915ca15998a83b410f3f8fac027f797ee7ca
Refs: #3098
diff --git a/tests/unit-tests/security/signature-sha256-with-ecdsa.t.cpp b/tests/unit-tests/security/signature-sha256-with-ecdsa.t.cpp
index 448734b..c54ee4c 100644
--- a/tests/unit-tests/security/signature-sha256-with-ecdsa.t.cpp
+++ b/tests/unit-tests/security/signature-sha256-with-ecdsa.t.cpp
@@ -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).
  *
@@ -20,7 +20,6 @@
  */
 
 #include "security/signature-sha256-with-ecdsa.hpp"
-#include "security/key-chain.hpp"
 #include "security/validator.hpp"
 #include "util/scheduler.hpp"