New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  queryParams: ['tab'],
  tab: 'locations'
});

templates.application.hbs

<link rel="stylesheet" href="https://unpkg.com/[email protected]/css/tachyons.min.css"/>
<ul class="dt cf mv0 ph0 mw9 center w-100 list">
  <li class="dtc tc">
  	{{#link-to 'index' (query-params tab="locations") classNames="db link f4 pb3 pt4 gray" activeClass="dark-gray bb bw2 b--light-blue"}}
    	Locations
    {{/link-to}}
  </li>
  <li class="dtc tc">
    {{#link-to 'index' (query-params tab="inspections") classNames="db link f4 pb3 pt4 gray" activeClass="dark-gray bb bw2 b--light-blue"}}
      Inspections
    {{/link-to}}
  </li>
</ul>

twiddle.json

{
  "version": "0.10.5",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.8.0",
    "ember-data": "2.8.0",
    "ember-template-compiler": "2.8.0",
    "ember-testing": "2.8.0"
  },
  "addons": {}
}