title: How to insert gaps between rows?
body: <p>i want to have gaps between rows in my ng2-smart-table,
  <code>border-spacing</code> doesn't work.</p>
  
  <p>i've tried to use <code>ng-deep</code> by following answer
  <a href="https://github.com/akveo/ng2-smart-table/issues/504#issuecomment-395478716" rel="nofollow noreferrer">https://github.com/akveo/ng2-smart-table/issues/504#issuecomment-395478716</a>
  but it doesn't work.
  other styles work, but not this one.</p>
  
  <pre><code>::ng-deep{
    .dark-table { // set a selector
        display: table;
        border-collapse: collapse;
        border-spacing: 6px;
        border-color: red;
        ...
  </code></pre>