Make sure kitchen test dependencies formulas are always fetched from correct branch

Change-Id: I7a46eebf602d04b2d91a63f1a1fa5e718f6bf83a
Related: PROD-29251
diff --git a/.kitchen.yml b/.kitchen.yml
index 5a065c2..7488a40 100644
--- a/.kitchen.yml
+++ b/.kitchen.yml
@@ -18,9 +18,11 @@
     - name: linux
       repo: git
       source: https://github.com/salt-formulas/salt-formula-linux
+      branch: <%=ENV['GERRIT_BRANCH'] || 'master' %>
     - name: contrail
       repo: git
       source: https://github.com/salt-formulas/salt-formula-opencontrail
+      branch: <%=ENV['GERRIT_BRANCH'] || 'master' %>
 
   state_top:
     base: