title: lodash: count values from array of objects
body: <p>I have an array of objects like this:</p>
  
  <pre><code>[
  {"question":"Q1","answer":"my answer 2"},
  {"question":"Q1","answer":"my answer"}
  {"question":"Q1","answer":"my answer"}
  {"question":"Q2","answer":"answer 2"}
  ]
  </code></pre>
  
  <p>I would like to group by the question keys and return the counts of each answer.</p>
  
  <p>e.g.</p>
  
  <pre><code>{
      "Q1": [{
          "answer": "my answer",
          "count": 2
      }, {
          "answer": "my answer 2",
          "count": 1
      }],
      "Q2": [{
          "answer": "answer 2",
          "count": 1
      }]
  }
  </code></pre>
  
  <p>,</p>
  
  <p>I am able to <code>groupBy</code> questions using:
  <code>.groupBy("question")</code> and count occurances of values using <code>.countBy()</code> but I am not sure how to combine the grouping and counting functions to achieve the desired output?</p>