[BUGFIX] Destroy components on teardown.

I was experiencing the issue in #64 and needed some way to properly tear down a component after a test was completed, otherwise lingering event observers hung around. This fix solved the issues that I was having. However, I wasn't quite sure how to test the fix, since the real work happens in the test teardown. So if anybody has an idea for how to test this, let me know and I'll add some tests.