title: How I can delete key and value in array of hash?
body: <p>I need delete all key created_at and updated_at in array of hashs . My hash looks like :</p>
  
  <pre><code>assessment_with_desc = {
    "id": 1,
    "name": "First assessment",
    "created_at": "2020-03-14T20:13:27.006Z",
    "updated_at": "2020-03-14T20:13:27.006Z",
    "description_with_child_models": [
      {
        "id": 3,
        "title": "First category",
        "created_at": "2020-02-20T15:32:46.379Z",
        "updated_at": "2020-03-14T20:16:11.530Z",
        "accessment_id": 1,
        "sub_categories": [
        {
          "id": 1,
          "title": "First sub_category",
          "category_id": 3,
          "created_at": "2020-02-20T15:40:49.793Z",
          "updated_at": "2020-02-20T15:40:49.793Z",
          "stages": [
          {
            "id": 5,
            "title": "First stage",
            "sub_category_id": 1,
            "created_at": "2020-02-20T15:44:10.603Z",
            "updated_at": "2020-02-20T15:44:10.603Z"
          }
         ]
        }
       ]
      }
    ]
  }
  </code></pre>
  
  <p>I did it, but it work only in this case <code>assessment_with_desc.delete('created_at')</code> and <code>assessment_with_desc.delete('updated_at')</code>: </p>
  
  <pre><code>assessment_with_desc.delete('created_at')
  assessment_with_desc.delete('updated_at')
  assessment_with_desc['description_with_child_models'].delete('created_at')
  assessment_with_desc['description_with_child_models'].delete('updated_at')
  assessment_with_desc['description_with_child_models'][0]['sub_categories'].delete('created_at')
  assessment_with_desc['description_with_child_models'][0]['sub_categories'].delete('updated_at')
  assessment_with_desc['description_with_child_models'][0]['sub_categories'][0]['stages'].delete('created_at')
  assessment_with_desc['description_with_child_models'][0]['sub_categories'][0]['stages'].delete('updated_at')
  </code></pre>