add encoding unit tests

Change-Id: I319a34a760742e6125e6a28c4ddc23fcf2f29cb3
diff --git a/tests/identity-management-fixture.hpp b/tests/identity-management-fixture.hpp
index 9b10dbf..9bae058 100644
--- a/tests/identity-management-fixture.hpp
+++ b/tests/identity-management-fixture.hpp
@@ -90,7 +90,7 @@
   security::Certificate
   addCertificate(const security::Key& key, const std::string& issuer);
 
-protected:
+public:
   KeyChain m_keyChain;
 };