If you're using Twig and/or LiipFunctionalTestBundle, make sure caching is enabled in your app/config/config_test.yml
Reduced time to build this project from 17 minutes to 4 :)
You don't mentioned about the this Bundle https://github.com/liip/LiipFunctionalTestBundle is required.
Updated making that more explicit, thanks for the nudge.
for me it's:
not the plural