add 3.1.0 release entry
diff --git a/ChangeLog b/ChangeLog
index 5417cc6..738f152 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,6 @@
+2018-11-28 Massimo Manghi <mxmanghi@apache.org>
+    * : Released as 3.1.0
+
 2018-11-24 Massimo Manghi <mxmanghi@apache.org>
     * .gitignore: update .gitignore