allow ca operator to see the secret code

Change-Id: I514e4be44525eeb7424678c18194b8968900dbf0
diff --git a/src/detail/ca-request-state.cpp b/src/detail/ca-request-state.cpp
index 739d717..53783d4 100644
--- a/src/detail/ca-request-state.cpp
+++ b/src/detail/ca-request-state.cpp
@@ -78,6 +78,9 @@
     os << "Challenge remaining tries:" << request.challengeState->remainingTries << " times\n";
     os << "Challenge remaining time: " << request.challengeState->remainingTime.count() << " seconds\n";
     os << "Challenge last update: " << time::toIsoString(request.challengeState->timestamp) << "\n";
+    std::stringstream ss;
+    boost::property_tree::write_json(ss, request.challengeState->secrets);
+    os << "Challenge secret: " << ss.str() << "\n";
   }
   os << "Certificate:\n";
   util::IndentedStream os2(os, "  ");