title: Dictionary value when deleting cell - unexpectedly found nil while unwrapping an Optional value
body: <p>Im working in Swift/Xcode and I am new to app development, i have a tableView with 2 labels. The issue is when deleting a cell of my tableView. I need to get the data of one of the cell labels but the app crashes with the fatal error - 'unexpectedly found nil while unwrapping an Optional value'</p>
  
  <p>I have set up break points so that i can check if the dictionary has anything stored in it, which it does, there is an element stored in it.</p>
  
  <p>Appreciate any help</p>
  
  <pre><code> func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
    if editingStyle == UITableViewCellEditingStyle.Delete {
      let cell = tableView.cellForRowAtIndexPath(indexPath) as! myCustomCell
  
         self.cost = self.total
        // This line gives me the error** self.total = self.cost - self.dict[cell.cellPrice.text!]!
         self.totalLabel.text = "Total: \(self.total)"
  
         self.dict.removeValueForKey(cell.cellTitle!.text!)
         tableView.reloadData()
         saveState()
  
  
  
  }
  </code></pre>
  
  <p>This my code to set up the cell: </p>
  
  <pre><code>func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -&gt; UITableViewCell { 
     let cell: myCustomCell = tableView.dequeueReusableCellWithIdentifier("customCell", forIndexPath: indexPath) as! myCustomCell 
     var myDataSource : [String] = Array(self.dict.keys) 
     let key = myDataSource[indexPath.row] as String 
     cell.cellTitle?.text = myDataSource[indexPath.row] 
     cell.cellPrice?.text = "£(self.dict[key]!)"
     self.saveState() 
     return cell 
  }
  </code></pre>