cell.delegate = self does't work in swift : I am trying to use https://github.com/MortimerGoro/MGSwipeTableCell this library to make custom swipe cell. However, cell.delegate = self keep giving me error saying that "Cannot assign value of type 'AlarmTableViewController' to type 'MGSwipeTableCellDelegate?'" but even if I insert ' as! MGSwipeTableCellDelegate' it makes fatal error: unexpectedly found nil while unwrapping an Optional value. 


```
class AlarmTableViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
```

``` func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell{
        let reuseIdentifier = "programmaticCell"
        var cell = tableView.dequeueReusableCell(withIdentifier: reuseIdentifier, for: indexPath) as! MGSwipeTableCell
        
        cell.textLabel!.text = "Title"
        cell.delegate = self as! MGSwipeTableCellDelegate //optional
        return cell
    }
```


In my storyboard I've set cell's custom class as MGSwipeTableCell and its Identifier as programmaticCell. Please help me. table view is driving me crazy. 