I'm trying to get up to speed on integrating tests into a simple plugin I wrote. I wrote a couple of tests that ensure my module injects the expected code into a template. I believe this would be considered to be an "author's test" and wouldn't need to run upon installation. Does that mean I should create an "xt/" directory with my plugin distribution and put my tests in there? Regarding tests for installation, which I believe should go in the "t/" directory, which tests should I write for that?