Apply fix for #823 to PhptTestCase runner
Simplified the composer install.

The only steps required to have a fully functional version of PHPUnit are:

    git clone git@github.com:sebastianbergmann/phpunit.git
    cd phpunit
    composer install --dev
Use composer to install `phpunit/php-invoker`.
Merge pull request #828 from whatthejeff/composer_autoload
Contributing is a bit easier now.
Merge pull request #829 from whatthejeff/contrib_update
Revert "Skip this test for now"

This reverts commit 9d97a3ed2b9a22b405f1bcb75ee30b82da712540.
Rephrase