types fixes, konva-node updates

konva-node/demo.js

@@ -62,6 +62,10 @@ setTimeout(function() {
               err && console.log(err);
               console.log('See out.png');
             });
+            // now try to create image from url
+            Konva.Image.fromURL(data, () => {
+              // shoul'd throw
+            });
           }
         });
       };

konva-node/index.js

@@ -26,6 +26,13 @@ Konva.Util.createCanvasElement = () => {
   return node;
 };
 
+// create canvas in Node env
+Konva.Util.createImageElement = () => {
+  const node = new canvas.Image();
+  node.style = {};
+  return node;
+};
+
 // _checkVisibility use dom element, in node we can skip it
 Konva.Stage.prototype._checkVisibility = () => {};