Basic command-line tools to export KEK and KDKs

Change-Id: I0975871b6639653e60a2f7ccefaf435147828f33
diff --git a/src/access-manager.cpp b/src/access-manager.cpp
index 3ab89f0..5fb34ab 100644
--- a/src/access-manager.cpp
+++ b/src/access-manager.cpp
@@ -80,7 +80,7 @@
   m_face.unsetInterestFilter(m_kdkRegId);
 }
 
-void
+Data
 AccessManager::addMember(const Certificate& memberCert)
 {
   Name kdkName(m_nacKey.getIdentity());
@@ -118,6 +118,8 @@
   m_keyChain.sign(*kdk, signingByIdentity(m_identity));
 
   m_ims.insert(*kdk);
+
+  return *kdk;
 }
 
 void