Support ensure => absent for defined types

[mkrakowitzer]

I am unable to ensure a defined type is absent, only up or down.

network_aliases:
  'eth0:2':
    ensure:    'absent'

Error: Could not retrieve catalog from remote server: Error 400 on SERVER: Must pass ipaddress to Network::Alias[eth0:8] on node fhl-r1papppp01.fnb.co.za
Warning: Not using cache on failed catalog
Error: Could not retrieve catalog; skipping run

network::alias::range appears as if it might support this, other defined types should too.

[razorsedge]

As listed under Issues in the README: There is presently no support for removing an interface.

I probably will not have the cycles to add this functionality, but PRs will be accepted.