[Glimmer 2] Component Integration Tests

[dfreeman]

In a freshly-minted app using the Ember alpha released today, integration tests fail.

Here's a repo reproducing the issue, which just followed these steps:

ember new test-app
cd test-app
bower install -S ember#alpha
ember g component-test fails
ember test

[rwjblue]

I fixed the direct issue reported here in #13970 and emberjs/ember-test-helpers#167, but the reproduction steps are still an issue due to the way top level outlets are being used by ember-test-helpers.

[rwjblue]

More work being done in:

• Migrate remainder of outlet tests to new testing setup. #13980
• Start working on making the alpha pass. ember-test-helpers#168

[rwjblue]

With the changes from ember-test-helpers@0.5.29 a basic this.render should be working (submitted dfreeman/glimmer-integration-failure#1 to the test repo).

A generic ember g component x-foo will still fail due to the lack of support for this.clearRender() in ember-test-helpers at the moment (still working on that).

[rwjblue]

As of ember-test-helpers@0.5.30 ember g component it-works passes without change. I submitted dfreeman/glimmer-integration-failure#2 to demonstrate.

I'm going to consider this finished (though please chime in if there are issues and I'll reopen).