title: Permitting array of hashes rails 5
body: <p>My rails version is 5 and I have request param like this,</p>
  
  <pre><code>{ "segment": {
      "name": "test",
      "new_filters": [
        {"criteria": "sad",
          "other_keys": [{"key": "value"}]
        }, 
        {"criteria": "sad",
          "other_keys1": [{"key1": "value1"}]
        }]
  }
  }
  </code></pre>
  
  <p>I am stuck in permitting the new_filter params in rails controller, 
  I am trying below code, </p>
  
  <pre><code>params.require(:segment).permit(:name, :people_count, new_filters: [])
  </code></pre>
  
  <p>and still getting the error. But this is not the case while having array of strings in new_filter key.
  Eg: ["sad", "asdasd"]. How to get the nested structure as whitelisted attribute?</p>