title: Format Moment.js am/pm to include periods/dots
body: <p>I'm running into a small formatting issue with moment's <code>a</code> input. </p>
  
  <p>a/A will return AM/am PM/pm but is there a way to format this to include periods?</p>
  
  <p>I.E. <strong>a.m. p.m.</strong> it's a format change that is important to the client and I haven't been able to find the fix with moment's documentation </p>
  
  <p>I've tried</p>
  
  <pre><code>moment.updateLocale('en', {
      meridiem : {
          am : 'a.m.',
          AM : 'A.M.',
          pm : 'p.m.',
          PM : 'P.M.'
      }
  }); 
  </code></pre>
  
  <p>With no success</p>
  
  <p>Is it possible? </p>