README update please

I'm struggling to only run certain tests since upgrading to version 0.2.1. I've had some success when running tests in the browser by overriding loadModules or adding an include matcher function but this doesn't seem to work when running on the command line.

I see the README hasn't been updated for a year but the implementation was updated a couple of months ago - any chance you could please update the README or let me know the correct approach and I'll update it and add a PR? Is there a place other than tests/index.html in my ember-cli project that I should be defining the override or adding that matcher function for the inclusion/exclusion to run on the command line?

Thanks!