Track status of 2 variables in wunderio git: WUNDERIO_GLOBAL_CACHE_ROOT and WUNDERIO_GLOBAL_CACHE_WUNDERIO

[hkirsman]

These are urls to search for:
https://github.com/search?q=org%3Awunderio+WUNDERIO_GLOBAL_CACHE_ROOT&type=code
https://github.com/search?q=org%3Awunderio+WUNDERIO_GLOBAL_CACHE_WUNDERIO&type=code

We removed these variables in https://github.com/wunderio/ddev-wunderio-drupal/pull/36/changes#diff-568e062c574c036c3a7a17a1be770589de71c0cded116a45b082dcb9697e612e

I'm a bit worried it breaks something somewhere although it should not. Let's keep track of the variable being deleted in these repos.