Update the NDNCERT library to version NDNCERT v2

spec:[https://github.com/named-data/ndncert/wiki/NDNCERT-Protocol-new]

Change-Id: Ia480a8e70c4b38ca170dfe2fcf50d1265ab65f46
diff --git a/src/ca-storage.cpp b/src/ca-storage.cpp
index ebe5c98..fbdae64 100644
--- a/src/ca-storage.cpp
+++ b/src/ca-storage.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2017-2018, Regents of the University of California.
+ * Copyright (c) 2017-2019, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *