(PUP-2569) Revoke all certificate matching a given name

`puppet cert revoke <name>` was revoking only the first certificate of the inventory file when the certificate file wasn't present on the system. This patch makes sure all issued certificates matching `name` are now revoked.

This PR replaces @dalen's one (with his permission) (https://github.com/puppetlabs/puppet/pull/2501), therefore I think it should be closed.

Please review and comment.
Thanks!