Fixes #1334

Kubelet gets copied from hyperkube container and run locally.

- Fix when clauses in various places
- Update requirements.txt
- Fix README.md

Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

When VPC is used, external DNS might not be available. This patch change
behavior to use metadata service instead of external DNS when
upstream_dns_servers is not specified.

Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

According to code apiserver, scheduler, controller-manager, proxy don't
use resolution of objects they created. It's not harmful to change
policy to have external resolver.

Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

kubernetesUnitPrefix was changed to k8s_* in 1.5. This patch reflects
this change in kargo

If this path doesnt exist, it will cause kubelet to fail to start when
using rkt

1.5 kubelet fails to start when using unknown params

- Renaming templates for netchecker
- Add dnsPolicy: ClusterFirstWithHostNet to kube-proxy

Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

In kubernetes 1.6 ClusterFirstWithHostNet was added as an option. In
accordance to it kubelet will generate resolv.conf based on own
resolv.conf. However, this doesn't create 'options', thus the proper
solution requires some investigation.

This patch sets the same resolv.conf for kubelet as host

Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

Necessary to persist this directory for host-local IPAM used by Canal
Add pre-upgrade task to copy /var/lib/cni out of old kubelet.

Fixes #1190