Fixed the background issue (#37)

Author: aaaprocess

widget/app.js

@@ -107,7 +107,7 @@
               }, function (err, imgUrl) {
                 if (imgUrl) {
                   img = imgUrl;
-                  element.attr("style", 'background:url(' + img + ') !important');
+                  element.attr("style", 'background:url(' + img + ') !important;background-size:cover !important');
                 } else {
                   img = '';
                   element.attr("style", 'background-color:white');