message: remove explicit lifetimes in integration example
diff: @@ -29,10 +29,7 @@ impl Controls {
  }
  }
  - pub fn view<'a>(
  - &'a mut self,
  - scene: &Scene,
  - ) -> Element<'a, Message, Renderer> {
  + pub fn view(&mut self, scene: &Scene) -> Element<Message, Renderer> {
  let [r, g, b] = &mut self.sliders;
  let background_color = scene.background_color;
  