removes jQuery from the tests & demo app

[ef4]

Thanks mostly to @cibernox's hard work we have nearly everything working without jQuery.

The final issue is that there are some acceptance tests that use checkbox, and apparently Ember's own checkbox component depends on jQuery until very recently.

[cibernox]

@ef4 to fix tests in < 3.0 you only have to modify the ember-try config to add ember-native-dom-event-dispatcher to 2.X scenarios

[cibernox]

Example:

    {
      name: 'ember-lts-2.12',
      npm: {
        devDependencies: {
          'ember-native-dom-event-dispatcher': '^0.6.4',
          'ember-source': '~2.12.0'
        }
      }
    },

[ef4]

Yup, I just figured that out from looking at what some of your addons are doing. :-)