keylime_server multihost test should remove keylime

[kkaarreell]

On attestation server, before running the system role we should remove all keylime packages and possibly also delete /etc/keylime and /var/lib/keylime (except copied certs) to make sure the role handles keylime installation.
Maybe, we could even store certs in a different location.

This change should be done in main and all rhel-* branches.