Fix doubleclick add (#2987)

* Fix redraw order

* Fix error when option is not defined

* Allow template labels

* Add .travis.yml file

* Add experiment travis code

* Fix react example

* Fix adding items with double click

lib/timeline/component/ItemSet.js

@@ -2044,6 +2044,10 @@ ItemSet.prototype._onAddItem = function (event) {
         newItemData.end = snap ? snap(end, scale, step) : end;
       }
     } else {
+      newItemData = {
+        start: snap ? snap(start, scale, step) : start,
+        content: 'new item'
+      };
       newItemData[this.itemsData._fieldId] = util.randomUUID();
 
       // when default type is a range, add a default end date to the new item