Support for Salt Carbon

Change-Id: I0cd20a8fcd618129c5ee0cbcb6e20475e7364608
diff --git a/horizon/server/multi/site.sls b/horizon/server/multi/site.sls
index 178d5fb..ed503a1 100644
--- a/horizon/server/multi/site.sls
+++ b/horizon/server/multi/site.sls
@@ -54,7 +54,11 @@
   git.latest:
   - name: {{ app.source.address }}
   - target: /srv/horizon/sites/{{ app_name }}/extra
+  {%- if grains.saltversioninfo.0 > 2015 %}
+  - branch: {{ app.source.revision }}
+  {%- else %}
   - rev: {{ app.source.revision }}
+  {%- endif %}
   - depth: 1
   - submodules: True
   - require: