Add salt-master and salt-minion alerts

Change-Id: I1407f89306b192ace13752f1fbc0a8594310aead
diff --git a/metadata/service/support.yml b/metadata/service/support.yml
index d61c6da..6472c6c 100644
--- a/metadata/service/support.yml
+++ b/metadata/service/support.yml
@@ -5,6 +5,8 @@
     _support:
       telegraf:
         enabled: true
+      prometheus:
+        enabled: true
       collectd:
         enabled: false
       heka: