add yaml-plain-text support

to avoid issues when u want to define multi-line var,

ex:

variable: |
  foo
  bar
  fobaaar
related bug: https://mirantis.jira.com/browse/PROD-12806
Change-Id: I6fdd42b39ad06ff5849125de71738358c234d316
diff --git a/rundeck/client/secret.sls b/rundeck/client/secret.sls
index 7625bfb..d6ffb2d 100644
--- a/rundeck/client/secret.sls
+++ b/rundeck/client/secret.sls
@@ -10,7 +10,7 @@
   rundeck_secret.present:
     - name: {{ path }}
     - type: {{ secret['type'] }}
-    - content: {{ secret['content'] }}
+    - content: {{ secret['content'] | yaml_encode }}
     {%- if grains.get('noservices', False) %}
     - onlyif: 'false'
     {%- endif %}