title: Merge a 1d and a 2d array based on shared string value and use default values where data is missing
body: <p>I want to merge a 2-dimensional array with a flat array of contiguous dates to generate an array of user scores for all dates.  Not all dates have a corresponding row with a score, so the value should default to zero.</p>
  <p>User data array:</p>
  <pre><code>$data = [
      ['New User', '2017-07-10', '12'],
      ['New User', '2017-07-11', '6'], 
      ['New User', '2017-07-13', '19']
  ];
  </code></pre>
  <p>Week dates array:</p>
  <pre><code>$datesArr = [
      '2017-07-10', 
      '2017-07-11', 
      '2017-07-12', 
      '2017-07-13', 
      '2017-07-14', 
      '2017-07-15', 
      '2017-07-16', 
      '2017-07-17'
  ];
  </code></pre>
  <p>Desired output:</p>
  <pre><code>[
      ['New User', '2017-07-10', '12'],
      ['New User', '2017-07-11', '6'], 
      ['New User', '2017-07-12', '0'],
      ['New User', '2017-07-13', '19']
      ['New User', '2017-07-14', '0'],
      ['New User', '2017-07-15', '0'],
      ['New User', '2017-07-16', '0'],
      ['New User', '2017-07-17', '0'],
  ]
  </code></pre>