Its seems that the splitted packages are currently just a copy out from this main repo.
Currently the Testrunner cannot be autoloaded and the filenames are still lowercase, which prevents from installing correctly. ( i had a PR, but then noticed it's corrected here partly already)
https://github.com/WhichBrowser/Testrunner
I think correct would be to develop the Testrunner at the Testrunner repo and include it here as composer dependency. Or another way would be a git submodule.
But having just a copy of the sources will always lead to differences.
What do you think?