Merge pull request #255 from aboe76/minion_engines_reactors

add engine and reactor config to salt minion configuration

pillar.example

     auth_keytab: /root/auth.keytab
     auth_principal: kadmin/admin
 
+		# optional engine configuration
+    engines:
+      slack:
+        token: xoxp-XXXXX-XXXXXXX
+        control: True
+        valid_users:
+          - someuser
+          - otheruser
+        valid_commands:
+          - test.ping
+          - list_jobs
+        aliases:
+          list_jobs:
+            type: runner
+            cmd: jobs.list_jobs
+
+
   # salt cloud config
   cloud:
     master: salt