Adding atomix version in 2.7 release notes

Change-Id: I4d91d7553cbb8e5fa96159db2c6752de326ff091
diff --git a/.gitreview b/.gitreview
index 94a12ba..582ed52 100644
--- a/.gitreview
+++ b/.gitreview
@@ -3,3 +3,4 @@
 port=29418
 project=voltha-docs.git
 defaultremote=origin
+defaultbranch=voltha-2.7