Rename the root PHPUnit configuration file and enable strict mode in all
Attempt to speed up Travis-CI builds

 - Comment out reporting in phpunit.xml.dist : prevent Travis-CI from generating unneeded reports
 - Disable GC when running composer : https://github.com/composer/composer/pull/3482#issuecomment-65131942
Git to ignore phpunit.xml files.
Disable Scrutinizer's external_code_coverage tool