update getMinions parameter

expect target to be expression and wraip it internaly

Change-Id: Ic4f0097bf8473ef3e2aa45742937759a06dd641c
diff --git a/src/com/mirantis/mk/Salt.groovy b/src/com/mirantis/mk/Salt.groovy
index 5bb9e81..e8017ad 100644
--- a/src/com/mirantis/mk/Salt.groovy
+++ b/src/com/mirantis/mk/Salt.groovy
@@ -219,7 +219,7 @@
  * @return list of active minions fitin
  */
 def getMinions(master, target) {
-    def minionsRaw = runSaltCommand(master, 'local', target, 'test.ping')
+    def minionsRaw = runSaltCommand(master, 'local', ['expression': target, 'type': 'compound'], 'test.ping')
     return new ArrayList<String>(minionsRaw['return'][0].keySet())
 }