[CLEANUP] upgrade to ember-cli 2.18.0

[GavinJoyce]

I'm unsure if there is a reason why we're using ember-cli 2.10.0 or not. This PR upgrades it to 2.18.0 if there isn't

[GavinJoyce]

Seems to be failing due to a duplicate file:

[GavinJoyce]

ember new now creates an app/templates/application.hbs file which is causing ember generate route application to hang on an Overwrite app/templates/application.hbs prompt

[rwjblue]

We can probably avoid that by changing the name of the route we generate? I don't think that application was a terribly intentional choice...

[GavinJoyce]

I think it was intentional, it seems to be testing that an application route isn't added to router.js:

it('route application', function() {
  return emberGenerate(['route', 'application']).then(() => {
    expect(file('app/router.js')).to.not.contain('this.route(\'application\')');
  });
});

[GavinJoyce]

I'll just remove app/templates/application.hbs before running the command

[rwjblue]

Good idea 👍

[GavinJoyce]

CI test failure seems to be flakiness

[rwjblue]

restarted browserstack