I would like to understand more about how this works and how to utilize it properly. I do know It’s not available in the latest version of Magento installed by Composer. You need to install Magento via Github and use the 2.2-develop branch. https://github.com/magento/magento2
For instance, currently I don't see the directory /dev/tests/acceptance/. (Installed with Composer commerce edition 2.2.3)
I've read through the docs here: http://devdocs.magento.com/guides/v2.1/mtf/mtf_introduction.html
Can someone break it down in some more simplified terms/steps.