Add qunit role for CLI QUnit testing
Add qunit role for CLI QUnit testing

Added as a separate role because it requires the chromium package
which is >200M.

Change-Id: Ieb22cf188c2635f90efd797bec04310fa703c3bf

wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant