Gather facts about server's IP addresses

Description

Sometimes you just want to know your server's IP.

Proposal

Use facts set by os_server_facts:

"openstack_servers": [
  {
    ...
    "addresses": {
      "krepe-network": [
        {
          "OS-EXT-IPS-MAC:mac_addr": "fa:bd:ac:aa:25:f0", 
          "OS-EXT-IPS:type": "fixed", 
          "addr": "10.0.0.8", 
          "version": 4
        }, 
        {
          "OS-EXT-IPS-MAC:mac_addr": "fa:16:3e:bd:ac:aa", 
          "OS-EXT-IPS:type": "floating", 
          "addr": "153.11.997.64", 
          "version": 4
        },
        ...
      ],
      ...
    },
    ...
  ]