daemon: mark some classes and methods 'final'

As suggested by gcc's -Wsuggest-final-types and -Wsuggest-final-methods

Change-Id: I1622857ee53581efd0c6ce3fe93199c72202d817
diff --git a/daemon/mgmt/rib-manager.hpp b/daemon/mgmt/rib-manager.hpp
index 3b2e794..98739f0 100644
--- a/daemon/mgmt/rib-manager.hpp
+++ b/daemon/mgmt/rib-manager.hpp
@@ -46,7 +46,7 @@
  * @brief Implements the RIB Management of NFD Management Protocol.
  * @sa https://redmine.named-data.net/projects/nfd/wiki/RibMgmt
  */
-class RibManager : public ManagerBase
+class RibManager final : public ManagerBase
 {
 public:
   RibManager(rib::Rib& rib, ndn::Face& face, ndn::KeyChain& keyChain,
@@ -220,7 +220,7 @@
   setFaceForSelfRegistration(const Interest& request, ControlParameters& parameters);
 
   ndn::mgmt::Authorization
-  makeAuthorization(const std::string& verb) override;
+  makeAuthorization(const std::string& verb) final;
 
 private: // Face monitor
   void