Prepare 0.5.0 release

Small fix to properly handle ndnsec identity check message and also update copyright years in several files.

Change-Id: I1fae8749f7d755f4af1ccca519c236480ff3f824
diff --git a/docs/authors.rst b/docs/authors.rst
new file mode 100644
index 0000000..94292d0
--- /dev/null
+++ b/docs/authors.rst
@@ -0,0 +1 @@
+.. include:: ../AUTHORS.rst
\ No newline at end of file