wrong css class for widget-int

IPython/html/static/widgets/js/widget_int.js

@@ -290,7 +290,7 define([
              * Called when view is rendered.
              */
             this.$el
-                .addClass('widget-hbox widget-text');
+                .addClass('widget-hbox widget-numeric-text');
             this.$label = $('<div />')
                 .appendTo(this.$el)
                 .addClass('widget-label')