update header files in tests

Change-Id: Ibfffb9367349f58eeb193350bad34fdfccd8c553
diff --git a/tests/unit-tests/crypto-helper.t.cpp b/tests/unit-tests/crypto-helper.t.cpp
index 8f8d7c0..28fbe63 100644
--- a/tests/unit-tests/crypto-helper.t.cpp
+++ b/tests/unit-tests/crypto-helper.t.cpp
@@ -19,7 +19,7 @@
  */
 
 #include "crypto-support/crypto-helper.hpp"
-#include "identity-management-fixture.hpp"
+#include "test-common.hpp"
 
 namespace ndn {
 namespace ndncert {