title: TapGesture is not working in Xcode 11.0 Beta
body: <p>Playing around with SwiftUI and this TapGesture() (or any other gesture) doesn't seem to work for me in a Cocoa app for MacOS, despite <code>@available(iOS 13.0, OSX 10.15, tvOS 13.0, watchOS 6.0, *)</code> when I View Definition on TapGesture. </p>
  
  <pre><code>import SwiftUI
  
  struct CircleView : View {
      var body: some View {
          Circle()
              .fill(Color.blue)
              .frame(width: 400, height: 400, alignment: .center)
              .gesture(
                  TapGesture()
                      .onEnded { _ in
                          print("View tapped!")
                  }
              )
      }
  }
  
  #if DEBUG
  struct CircleView_Previews : PreviewProvider {
      static var previews: some View {
          CircleView()
      }
  }
  #endif
  
  </code></pre>
  
  <p>The Build succeeded, I'm viewing the Circle in Preview and I have the console open, but nothing seems to print.</p>
  
  <p>Am I doing something wrong? Is this a 10.15 Beta bug? Is there another framework I need to import other than SwiftUI? New to Swift here.</p>