Added pulp::admin to install and configure pulp-admin tool

Makes it easier to add pulp-admin to the server or another admin machine.
This setting is actually a bug in Pulp 2.4 and has been fixed in master (https://github.com/pulp/pulp/blob/master/client_admin/etc/pulp/admin/admin.conf#L27)

It should be '/etc/pki/tls/certs/ca-bundle.crt'