Colin O'Dell, as mentioned on his blog, has put together the instructions for something he calls "PHPUnicorn" (not to be confused with the PHP Unicorn conference) - a real-time system for visualizing unit test results via a Raspberry Pi, some LEDs and a Unicorn pHAT board.
For Pi Day 2017 I created a really fun project - the PHPUnicorn!
A simple PHPUnit listener collects test results and sends them to a Raspberry Pi Zero Wireless device in real-time. As the device receives the stats it lights up LEDs green, red, or orange to visualize the progress and results of your unit tests.
The full instructions are over in this article on the Hackster.io site providing you with a list of the components needed, how you'll need to extend PHPUnit with a custom listener and a simple Python script to interface with the Pi and Unicorn board. The end result is a set of LEDs on the board showing the progress (and failures) of your unit tests being run.