DER encoding: added PrintVisitor.
diff --git a/Makefile.am b/Makefile.am
index f2e717f..46d6352 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -121,6 +121,7 @@
   ndn-cpp/encoding/der/der.cpp ndn-cpp/encoding/der/der.hpp \
   ndn-cpp/encoding/der/visitor/certificate-data-visitor.cpp ndn-cpp/encoding/der/visitor/certificate-data-visitor.hpp \
   ndn-cpp/encoding/der/visitor/no-arguments-visitor.cpp ndn-cpp/encoding/der/visitor/no-arguments-visitor.hpp \
+  ndn-cpp/encoding/der/visitor/print-visitor.cpp ndn-cpp/encoding/der/visitor/print-visitor.hpp \
   ndn-cpp/encoding/der/visitor/public-key-visitor.cpp ndn-cpp/encoding/der/visitor/public-key-visitor.hpp \
   ndn-cpp/encoding/der/visitor/simple-visitor.cpp ndn-cpp/encoding/der/visitor/simple-visitor.hpp \
   ndn-cpp/encoding/der/visitor/visitor.hpp \