Ember leaflet on not showing on changing hidden property is displays but not properly

I am using Ember-leaflet for my ember application. I followed every step from installation to usage but somehow it is not showing anything. I inspected the elements and found property overflow:hidden. I changed to overflow:visible then map was showing but on zooming in and out, image expands awkwardly.

I am using in my template.hbs

and in my controller.js

export default Ember.Controller.extend({ lat: 45.519743, lng: -122.680522, zoom: 10 }); reference used from http://ift.tt/2bsrAEd . Any help?