Tutorial: Integration test fails on triggerKeyEvent().

[rayascott-zz]

From Autocomplete Component under the heading "An Integration Test" (and just before the heading "Application Tests") the test in file tests/integration/components/list-filter-test.js ("should update with matching listings") fails due to no element passed to triggerKeyEvent() call. This failure also applies to the test "should initially load all listings".

Although I've only looked at Ember for less than 2 days, I get the impression this error is caused by the fact that class .list-filter does not exist on the input HTML tag generated by the list-filter component.

[acorncom]

@rayascott Moving this as well.