Add support for phpunit testing in Drupal 8

[markdboyd]

We need to support PHPUnit testing for Drupal 8.

• Is PHPUnit unnecessarily slow with grunt or virtual environments?
• How can we allow running phpunit for just some packages while also making grunt test run all the tests?

Original Post

On a freshly built GDT project, running the PHPunit tests often takes over a minute, even though there are no tests defined. I suspect that PHPUnit may be unnecessarily scanning folders besides "modules/custom". I tried to alter this behavior by configuring phpunit.xml.dist, but to no effect.

I also see this note from @jhedstrom on #121. I tried using that command to run PHPUnit tests, but got errors related to Simpletest module not being installed.

I should also note that my project runs on Docker containers on a Phase2 devtools managed VM, so perhaps the virtualization could be part of the root issue here.

[mike-potter]

The slowdown is related to using NFS within the P2 devtools docker container. It's very possible that there is still a fix to be made to PHPUnit to help with this (similar to recent fixes in Drush and Drupal/core), but the ultimate solution with the P2 devtools is to move away from NFS.

I don't see anything specific that GDT itself is doing that would cause this.

[markdboyd]

I'm no expert on file systems, but I do know that we moved towards NFS because it was incredibly more stable than what we were using before (vboxFS)