Support for PHP 7.1 ended December 2018 Security support runs until DEC 2019.
All PHP development should be on PHP 7.2 or later.
phpunit version 8 is the current version and we're using 4.8. phpunit8 requires PHP 7.2.
phpunit7 requires php 7.1 and has fewer breaking changes.
These changes will drop support for PHP < 7.1. Ubuntu xenial build job will stop building php.
Folks who need PHP support for versions before 7.1 can use version 0.12.0 which is already released.
The code may actually work, but we should keep up with the ecosystem.