add rivet 3.0.2 release changelog entry
diff --git a/ChangeLog b/ChangeLog
index 2142fcb..1ebd42c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,6 @@
+2018-07-07 Massimo Manghi <mxmanghi@apache.org>
+    * Changelog: released as rivet 3.0.2
+
 2018-06-25 Massimo Manghi <mxmanghi@apache.org>
     * rivet/init.tcl.it: the error handler of error scripts requires
     ::Rivet::script to keep the actual 'script' being run