Many PHP projects now supply PHPUnit via require-dev in composer.
This means that to run PHPUnit, you often have to supply a full path
to the local phpunit binary.
This package is intended to be installed globally, and supplies you with a
phpunit script as well.
This script will automatically find a composer.json in your current path
or one of its parents, and find the correct "local" phpunit script and
runs it for you.
In addition to that, it will also attempt to find phpunit.xml or
phpunit.xml.dist and change the working directory to that path before
running the real phpunit script.
This means that using this script, you can just invoke phpunit from wherever
you are in your project, and it will run it correctly.
composer global require evert/phpunit-bin
Make sure that after you run that, your global composer bin directory is
in your $PATH. This is usually ~/.composer/vendor/bin, or ~/.config/composer/vendor/bin