The new ansible.cfg file is copied from matrix-docker-ansible-deploy
and should provide better defaults for general purpose usage.
We've had instances of people wishing to run certain things like `just roles`
using a regular user and to actually run the playbook (`just install-all`) as `root`.
If both of these invocations try to write temporary files to `/tmp/mash*`, they run into a conflict.
It's probably better to avoid writing stuff to `/tmp` by default anyway.