selectedNodes not set on ready.jstree event

[ashrafhasson]

Hi, thanks for the great addon! :)

I had a need to disable a few (or all) nodes immediately after finishing loading based on some app state and logic but the ready.jstree doesn't seem to set the selectedNodes here which makes it difficult to tell what to disable for me. I've tested with setting the selectedNodes in this event hook and it seems to work well on the initial loaded content. Would you accept a PR if I add the following two lines into the ready.jstree event?

let selNodes = Ember.A(this.get('treeObject').jstree(true).get_selected(true));
this.set('selectedNodes', selNodes);

Thanks,

[ashrafhasson]

or maybe add the ready event to the list of selectionChangedEventNames which also works well.