puppet-keystone should default to enabled => false

[mellotron]

CentOS 7 now no longer ships a systemd unit for keystone:

https://lists.centos.org/pipermail/centos-devel/2016-November/015398.html

The default configuration for puppet-keystone should look like:

class { 'keystone':
  catalog_type => 'sql',
  admin_token => '...',
  database_connection => 'mysql://keystone:password@127.0.0.1/keystone',
  enabled => false,
}

class { '::keystone::wsgi::apache':
    ssl => false,
}