title: Double Quotation marks for html classes
body: <p>When using Rubocop, they specify to use single quotation marks rather than double quotation in possible places other than interpolation. So what about the views of a rails app. The classes in the views are written as follows,</p>
  
  <pre><code>&lt;div class="row-fluid"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Should this also be changed to single quotations? Do that have any performance change? I just want to know why does Rubocop prefer to use single quotation over double quotation.</p>