test travis with sudo=true instead of required

pin docker versions to 1.9 or earlier

Integration tests

weave network plugin

Force kube-proxy to bind to local address

split network plugins into distinct roles

fix some issues with fedora 23 and dnf

calico uses --ip option

Increase liveness timeout

add option '--nat-outgoing' for calico on clouds

install epel release for rhel

Update docker for CentOS issues in AWS and general variables

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.

etcd initd startup command fix

Change calico condition --ipip

Add --ipip to calico if on cloud_proivder

Add variables and defaults for multiple types of ip addresses.

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.

use 'kube_pods_subnet' var for flannel conf