ember modal dialog wont close

I have used ember-modal-dialog. I have set the modal to close (as per the example on git - http://ift.tt/1JBG5dZ). But it does not close when I click the background.

application.hbs

  
      abc
  

applications.js

export default Ember.Controller.extend({
    isShowingModal: false,
    actions: {
        showNavMenu: function() {
          this.toggleProperty('isShowingModal');
        }
    }
});