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

Change-Id: I7c9943153bb7e0c332ed31cd4d9d30b0259fe3b8
Related: PROD-29251
diff --git a/.kitchen.yml b/.kitchen.yml
index 5a730e3..a2ab0d2 100644
--- a/.kitchen.yml
+++ b/.kitchen.yml
@@ -18,15 +18,19 @@
     - name: linux
       repo: git
       source: https://gerrit.mcp.mirantis.com/salt-formulas/linux
+      branch: <%=ENV['GERRIT_BRANCH'] || 'master' %>
     - name: keystone
       repo: git
       source: https://gerrit.mcp.mirantis.com/salt-formulas/keystone
+      branch: <%=ENV['GERRIT_BRANCH'] || 'master' %>
     - name: apache
       repo: git
       source: https://gerrit.mcp.mirantis.com/salt-formulas/apache
+      branch: <%=ENV['GERRIT_BRANCH'] || 'master' %>
     - name: oslo_templates
       repo: git
       source: https://gerrit.mcp.mirantis.com/salt-formulas/oslo-templates
+      branch: <%=ENV['GERRIT_BRANCH'] || 'master' %>
   state_top:
     base:
       "*":