title: Sorting in Yajrabox datatable by Eloquent accessor field
body: <p>I have a users table with first_name and last_name fields, and an accessor getFullNameAttribute, that I´m displaying as an interactive table using Yajrabox datatable. I can show the table all right, with the 'fullName' accessor, but when I try to sort by this 'fullName' field, nothing really happens. The ajax call gets executed, but the sorting remains the same and no errors are reported. I can sort by any of the other fields and it works fine.
  Is there a sorting restriction on added model attributes for this package? Can´t seem to find anything on the docs.</p>
  
  <p>Thanks much!</p>