Adding atomix version in 2.7 release notes

Change-Id: I969a14ac522c33002e71444996d735bd3d47f9e1
diff --git a/release_notes/voltha_2.7.rst b/release_notes/voltha_2.7.rst
index 26e30a0..863ac1b 100644
--- a/release_notes/voltha_2.7.rst
+++ b/release_notes/voltha_2.7.rst
@@ -135,10 +135,11 @@
 Component Versions in VOLTHA 2.7 release
 ----------------------------------------
 
-ONOS:
-++++++++++
+ONOS and Atomix:
+++++++++++++++++
 
 - `ONOS 2.2 LTS <https://github.com/opennetworkinglab/onos/releases/tag/2.2.8>`_: ``2.2.8``
+- `ATOMIX <https://github.com/atomix/atomix/releases/tag/atomix-3.1.8>`_: ``3.1.8``
 
 ONOS Apps:
 ++++++++++