Merge pull request #19 from yoat/master

Implement iOS stretching fix

src/image-zoom.ios.ts

@@ -21,6 +21,7 @@ export class ImageZoom extends ImageZoomBase {
     public createNativeView() {
         this._image = UIImageView.new();
         this._image.clipsToBounds = true;
+        this._image.contentMode = UIViewContentMode.ScaleAspectFit;
         const nativeView = UIScrollView.new();
         nativeView.addSubview(this._image);
         nativeView.zoomScale = this.zoomScale;