use enum class for status

Change-Id: Iaba23e0754335a7fecec2d6c4b3446988b2fd9d0
diff --git a/src/challenge-module.hpp b/src/challenge-module.hpp
index 4cc5fa9..fb687e1 100644
--- a/src/challenge-module.hpp
+++ b/src/challenge-module.hpp
@@ -70,13 +70,13 @@
 
   // For Client
   virtual JsonSection
-  getRequirementForChallenge(int status, const std::string& challengeStatus) = 0;
+  getRequirementForChallenge(Status status, const std::string& challengeStatus) = 0;
 
   virtual JsonSection
-  genChallengeRequestJson(int status, const std::string& challengeStatus, const JsonSection& params) = 0;
+  genChallengeRequestJson(Status status, const std::string& challengeStatus, const JsonSection& params) = 0;
 
   virtual Block
-  genChallengeRequestTLV(int status, const std::string& challengeStatus, const JsonSection& params) = 0;
+  genChallengeRequestTLV(Status status, const std::string& challengeStatus, const JsonSection& params) = 0;
 
   // helpers
   static std::string