tests: Enable isolation of KeyChain during run of unit/integrated tests

Change-Id: Ia136e4bb074c14e8d824f563594cbc0ad7592c3b
Refs: #3655
diff --git a/tests/unit-tests/security/signature-sha256-with-rsa.t.cpp b/tests/unit-tests/security/signature-sha256-with-rsa.t.cpp
index 5c6f87d..ea3a40f 100644
--- a/tests/unit-tests/security/signature-sha256-with-rsa.t.cpp
+++ b/tests/unit-tests/security/signature-sha256-with-rsa.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2015 Regents of the University of California.
+ * Copyright (c) 2013-2016 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -31,7 +31,7 @@
 namespace tests {
 
 class SignatureSha256RsaTimeFixture : public UnitTestTimeFixture
-                                    , public security::IdentityManagementFixture
+                                    , public IdentityManagementFixture
 {
 public:
   SignatureSha256RsaTimeFixture()