PKI tokens have been actively deprecated from keystone and there are
deprecations being emitted from keystonemiddleware. Because of this we
no longer need an auth cache directory in the services where the PKI
certifcates used to be stored.
Remove the creation and use of all these AUTH_CACHE directories.
Change-Id: I5680376e70e74882e9fdb87ee1b95d5f40570ad7