[Swift]Remove border from bottom of Navigation bar

Memorandum

Delete border from bottom of Navigation bar.
ナビゲーションバーの境界線（下線）を消す

This is useful when put same color UI part below navigation bar.

 func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

// Add bellow lines at didFinishLaunchingWithOptions
  UINavigationBar.appearance().setBackgroundImage(UIImage(), for: UIBarMetrics.default)
        UINavigationBar.appearance().shadowImage = UIImage()

        return true
    }

Before

After