update to image 0.20 (#683)

examples/window_icon.rs

@@ -6,10 +6,9 @@ extern crate winit;
 #[cfg(feature = "icon_loading")]
 extern crate image;
 
-use winit::Icon;
-
 #[cfg(feature = "icon_loading")]
 fn main() {
+    use winit::Icon;
     // You'll have to choose an icon size at your own discretion. On X11, the desired size varies
     // by WM, and on Windows, you still have to account for screen scaling. Here we use 32px,
     // since it seems to work well enough in most cases. Be careful about going too high, or
@@ -37,7 +36,7 @@ fn main() {
             match event {
                 CloseRequested => return winit::ControlFlow::Break,
                 DroppedFile(path) => {
-                    use image::GenericImage;
+                    use image::GenericImageView;
 
                     let icon_image = image::open(path).expect("Failed to open window icon");