VOL-5143 - Create beta-release branch for voltctl

VERSION
-------
  o Bump version string for release.

.gitreview
----------
  o Assign branchdefault=voltha-2.12 for rebase and merge.

Change-Id: I41956bf76fe86863a6ea881abdcf92b95b48b3a0
diff --git a/.gitreview b/.gitreview
index dba8a92..170fcc2 100644
--- a/.gitreview
+++ b/.gitreview
@@ -3,3 +3,4 @@
 port=29418
 project=voltctl.git
 defaultremote=origin
+defaultbranch=voltha-2.12
\ No newline at end of file