test travis with sudo=true instead of required

install required packages before common

roles/kubernetes/preinstall/tasks/main.yml

variables.

1. AWS has issues with ext4 (use xfs instead for CentOS only)
2. Make sure all the centos config files are include in the systemd config
3. Make sure that network options are set in the correct file by os family

This allows downstream items like opencontrail and others change variables
in expected locations.

Each node can have 3 IPs.
1. ansible_default_ip4 - whatever ansible things is the first IPv4 address
   usually with the default gw.
2. ip - An address to use on the local node to bind listeners and do local
   communication.  For example, Vagrant boxes have a first address that is the
   NAT bridge and is common for all nodes.  The second address/interface should
   be used.
3. access_ip - An address to use for node-to-node access.  This is assumed to
   be used by other nodes to access the node and may not be actually assigned
   on the node.  For example, AWS public ip that is not assigned to node.

This updates the places addresses are used to use either ip or access_ip and walk
up the list to find an address.

files.  get_url doesn't honor owner and mode is spotty.

args are different.  Sigh.