title: Ngx-datatable cellClass not working
body: <p>I try to append my custom css to ngx-datatable cell.</p>
  
  <pre><code>&lt;ngx-datatable-column 
    *ngFor="let column of tableOptions.columnDefs"
    [cellClass]="'my-custom-cell'"
    ...
  </code></pre>
  
  <p>Css for <code>my-custom-cell</code> :</p>
  
  <pre><code>.my-custom-cell{
    padding: 0;
  }
  </code></pre>
  
  <p>In dev tools I can see <code>datatable-body-cell</code> has classes</p>
  
  <pre><code>class="datatable-body-cell my-custom-cell sort-active"
  </code></pre>
  
  <p>Problem is that no css is overridden</p>