Add tests

[pangratz]

This adds basic tests for the HTMLBars plugin using the existing ember-cli infrastructure. The plugin is added to the dummy apps' registry so all data-test-* attributes within the dummy app are stripped. Then a normal moduleForComponent integration test adds assertions for successfully stripped attributes.

Since the plugin itself is not located within app/ or tests/, the mocha JSHint test suite is setup to check for styling issues within the plugin.

ember-try is configured to run the tests using ember 1.13 and canary, beta as well as release channels.

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The functionality of the HTMLBars plugin itself is fully tested now. One thing that still bugs me is that there is no test for the addon itself: since it adds the plugin only in the production environment, it would be nice to have a smoke test which basically does the following:

ember new smoke-test-app
cd smoke-test-app
ember install ember-test-selectors
echo "<span data-test-id='my-id' ></span>" > app/templates/application.hbs
ember build --prod
# assert that the served application doesn't contain the `data-test-id` attribute

I am not sure how this would be achieved yet, so this is still missing 😢

Closes #1

[marcoow]

Yay, looks great! I think not having the activation tested is fine. At least the tests already test that the activation mechanism that we use works (https://github.com/simplabs/ember-test-selectors/pull/4/files#diff-2fe2a7faee7de1e0d5d82e032498d84cR14), we just don't have the specific lines in index.js covered.

[pangratz]

👯