**breaking change**: Switch Face and related classes to v2::KeyChain

security::v2::KeyChain is now exposed as ndn::KeyChain, which should
ensure that dependent code can be mostly compiled.  However, expect code
that explicitly uses the old KeyChain interface to be broken.

Change-Id: I7330d0250d92f3f0f2570ab6d0214ab3dfdd18cc
Refs: #3098
diff --git a/tools/ndnsec/main.cpp b/tools/ndnsec/main.cpp
index b86fee1..4dc7ee0 100644
--- a/tools/ndnsec/main.cpp
+++ b/tools/ndnsec/main.cpp
@@ -23,7 +23,7 @@
 
 #include "version.hpp"
 
-#include "security/key-chain.hpp"
+#include "security/v1/key-chain.hpp"
 #include "security/v1/certificate-subject-description.hpp"
 #include "security/v1/secured-bag.hpp"