With PHPUnit 8 knocking at our doors, we should add .phpunit.result.cache to .gitignore. This should be done where the following conditions are met:
- A .phpunit.xml(.dist) file (or more than one) exists; .phpunit.result.cache will be created by PHPUnit in the same directory as the XML file. Hence, for each XML file, the line to add is $xmlBaseDir/.phpunit.result.cache.
- If the repo requires PHPUnit >= 8; we may as well ignore this requirement, since all repos will require it sooner or later.