use Data::Dumper;
# Documentation links
+#XXX: see https://letsencrypt.github.io/acme-spec/
+#XXX: see http://www.rfc-editor.org/rfc/rfc7517.txt
#XXX: see ietf draft at https://ietf-wg-acme.github.io/acme/
#XXX: see javascript implementation https://github.com/diafygi/gethttpsforfree/blob/gh-pages/js/index.js