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

Change-Id: Ic4b6915ca15998a83b410f3f8fac027f797ee7ca
Refs: #3098
diff --git a/tests/unit-tests/security/validator-config.t.cpp b/tests/unit-tests/security/validator-config.t.cpp
index 2419e8d..74aab21 100644
--- a/tests/unit-tests/security/validator-config.t.cpp
+++ b/tests/unit-tests/security/validator-config.t.cpp
@@ -21,7 +21,7 @@
 
 #include "security/validator-config.hpp"
 
-#include "security/key-chain.hpp"
+#include "security/signing-helpers.hpp"
 #include "util/io.hpp"
 #include "util/scheduler.hpp"
 #include "util/dummy-client-face.hpp"