build: Upgrade underlying NFD/ndn-cxx to 0.7.1

Change-Id: I4d12cc9e30be57c9a2fd3a33732fba3f6616a24a
diff --git a/RELEASE_NOTES.rst b/RELEASE_NOTES.rst
index 6c76122..c23a72b 100644
--- a/RELEASE_NOTES.rst
+++ b/RELEASE_NOTES.rst
@@ -1,3 +1,8 @@
+Version 0.7.1-1
+---------------
+
+NFD and ndn-cxx updated to version 0.7.1
+
 Version 0.7.0-1
 ---------------