Retrieves a version for a single feature rule.
OK
{- "id": "featureRuleId",
- "version": 1,
- "tags": [ ],
- "label": "Test feature",
- "description": "Test feature",
- "requirements_script": "return []",
- "action_script": "return \"this is a test\"",
- "script_type": "javascript",
- "graph_state": "{\"property1\": \"value1\"}",
- "editing_mode": "manual",
- "last_updated": "2011-11-11T11:11:11.000"
}