/**
  * Approve Assignment
  *
  * @param $contract_id
  * @param $task_id
  * @return Redirect
  */
 public function approve($contract_id, $task_id)
 {
     if ($this->task->approveTask($contract_id, $task_id)) {
         return redirect()->back()->withSuccess(trans('mturk.action.approve'));
     }
     return redirect()->back()->withError(trans('mturk.action.approve_fail'));
 }