Update release notes for V 3.1.0-M3
This document contains the last changes of OrientDB Community Edition.
+-----------------------------------------------------------------------------------------------------------------------------------
+VERSION 3.1.0 M3 - (June, 30 2019)
+- Release Notes: https://github.com/orientechnologies/orientdb/wiki/OrientDB-3.1-Release-Notes#310M3---30-june-2019
-----------------------------------------------------------------------------------------------------------------------------------
VERSION 3.1.0 M2 - (October, 5 2018)
