Display time in Xcode 7

Question

I have problem with my code. Can anyone help me please?

Error: 2015-12-10 19:57:58.890 time[1177:36084] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason:
 '[<time.ViewController 0x79122de0> setValue:forUndefinedKey:]: this
 class is not key value coding-compliant for the key display.'
     *** First throw call stack:
     (
        0   CoreFoundation                      0x001fea14 __exceptionPreprocess + 180
        1   libobjc.A.dylib                     0x01eafe02 objc_exception_throw + 50
        2   CoreFoundation                      0x001fe631 -[NSException raise] + 17
        3   Foundation                          0x006501bc -[NSObject(NSKeyValueCoding) setValue:forUndefinedKey:] + 282
        4   Foundation                          0x005aa83a _NSSetUsingKeyValueSetter + 115
        5   Foundation                          0x005aa7bf -[NSObject(NSKeyValueCoding) setValue:forKey:] + 295
        6   UIKit                               0x00ba306d -[UIViewController setValue:forKey:] + 85
        7   Foundation                          0x005df01d -[NSObject(NSKeyValueCoding) setValue:forKeyPath:] + 384
        8   UIKit                               0x00e16cb4 -[UIRuntimeOutletConnection connect] + 132
        9   libobjc.A.dylib                     0x01ec400c -[NSObject performSelector:] + 62
        10  CoreFoundation                      0x0012ef51 -[NSArray makeObjectsPerformSelector:] + 273
        11  UIKit                               0x00e1534e -[UINib instantiateWithOwner:options:] + 2102
        12  UIKit                               0x00baaabc -[UIViewController _loadViewFromNibNamed:bundle:] + 429
        13  UIKit                               0x00bab4f4 -[UIViewController loadView] + 189
        14  UIKit                               0x00bab900 -[UIViewController loadViewIfRequired] + 154
        15  UIKit                               0x00bac1ed -[UIViewController view] + 35
        16  UIKit                               0x00a59f94 -[UIWindow addRootViewControllerViewIfPossible] + 69
        17  UIKit                               0x00a5a6b1 -[UIWindow _setHidden:forced:] + 304
        18  UIKit                               0x00a5aa67 -[UIWindow _orderFrontWithoutMakingKey] + 49
        19  UIKit                               0x00a6e118 -[UIWindow makeKeyAndVisible] + 80
        20  UIKit                               0x009d66e7 -[UIApplication _callInitializationDelegatesForMainScene:transitionContext:] + 4190
        21  UIKit                               0x009ddcd6 -[UIApplication _runWithMainScene:transitionContext:completion:] + 1989
        22  UIKit                               0x00a02ee5 __84-[UIApplication _handleApplicationActivationWithScene:transitionContext:completion:]_block_invoke3218 + 68
        23  UIKit                               0x009da966 -[UIApplication workspaceDidEndTransaction:] + 163
        24  FrontBoardServices                  0x03c37c76 __37-[FBSWorkspace clientEndTransaction:]_block_invoke_2 + 71
        25  FrontBoardServices                  0x03c3774d __40-[FBSWorkspace _performDelegateCallOut:]_block_invoke + 54
        26  FrontBoardServices                  0x03c55173 -[FBSSerialQueue _performNext] + 184
        27  FrontBoardServices                  0x03c555aa -[FBSSerialQueue _performNextFromRunLoopSource] + 52
        28  FrontBoardServices                  0x03c548a6 FBSSerialQueueRunLoopSourceHandler + 33
        29  CoreFoundation                      0x001186ff __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15
        30  CoreFoundation                      0x0010e38b __CFRunLoopDoSources0 + 523
        31  CoreFoundation                      0x0010d7a8 __CFRunLoopRun + 1032
        32  CoreFoundation                      0x0010d0e6 CFRunLoopRunSpecific + 470
        33  CoreFoundation                      0x0010cefb CFRunLoopRunInMode + 123
        34  UIKit                               0x009da206 -[UIApplication _run] + 540
        35  UIKit                               0x009dfbfa UIApplicationMain + 160
        36  time                                0x0001940c main + 140
        37  libdyld.dylib                       0x02913a21 start + 1
     )
     libc++abi.dylib: terminating with uncaught exception of type NSException
     (lldb)

and my code is:

//
//  ViewController.swift
//  time
//
//  Created by Marek on 09.12.15.
//  Copyright © 2015 Marek. All rights reserved.
//
import CoreFoundation
import CoreGraphics
import Darwin
import Foundation
import UIKit

class ViewController: UIViewController {


    @IBOutlet weak var currentTimeLabel: UILabel!

        var timer = NSTimer()

        override func viewDidLoad() {
            super.viewDidLoad()

            // Do any additional setup after loading the view, typically from a nib.

            self.timer = NSTimer.scheduledTimerWithTimeInterval(
                1.0,
                target: self,
                selector: Selector("tick"),
                userInfo: nil,
                repeats: true)
        }

        @objc func tick() {
            currentTimeLabel.text = NSDateFormatter.localizedStringFromDate(NSDate(),
                dateStyle: .MediumStyle,
                timeStyle: .MediumStyle)
        }
    }