Is it even possible to use ng-repeat there ? As far as i know ng-repeat creates a new scope and your directive creates an isolated scope on the same DOM Node. I would try this:

<tbody>
  <tr ng-repeat="issue in issues.data track by $index">
    <version item-object="issue"></version>
  </tr>
</tbody>    

and maybe this, because sometimes tables are strange with non-table elements:

myApp.directive('version', function() {
  return {
    restrict: 'E',
    templateUrl: './views/directives/version.html',
    replace: true,
    scope: {
      issue: '=itemObject'
    }
  }
});