Provide example of Kibana Spaces privilege in role configuration

[geekpete]

Feature Description

Kibana Spaces will require an "applications" block in the role to provide any access to even the default space, without it users might not be able to access Kibana.
Spaces might be in use for 6.8.x or later.

Example Role output from Security API:

{
  "spacetest_role" : {
    "cluster" : [ ],
    "indices" : [ ],
    "applications" : [
      {
        "application" : "kibana-.kibana",
        "privileges" : [
          "all"
        ],
        "resources" : [
          "*"
        ]
      }
    ],
    "run_as" : [ ],
    "metadata" : { },
    "transient_metadata" : {
      "enabled" : true
    }
  }
}

There's no applications section in the current examples for specifying roles in the README:
https://github.com/elastic/puppet-elasticsearch#roles