DER encoding: implement Certificate::encode.
diff --git a/Makefile.am b/Makefile.am
index 89c5386..f2e717f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -142,6 +142,7 @@
   ndn-cpp/transport/tcp-transport.cpp \
   ndn-cpp/transport/transport.cpp \
   ndn-cpp/transport/udp-transport.cpp \
+  ndn-cpp/util/blob-stream.hpp \
   ndn-cpp/util/blob.cpp \
   ndn-cpp/util/changed-event.cpp ndn-cpp/util/changed-event.hpp \
   ndn-cpp/util/dynamic-uint8-vector.cpp ndn-cpp/util/dynamic-uint8-vector.hpp \