Add etcd proxy support

* Enforce a etcd-proxy role to a k8s-cluster group members. This
provides an HA layout for all of the k8s cluster internal clients.
* Proxies to be run on each node in the group as a separate etcd
instances with a readwrite proxy mode and listen the given endpoint,
which is either the access_ip:2379 or the localhost:2379.
* A notion for the 'kube_etcd_multiaccess' is: ignore endpoints and
loadbalancers and use the etcd members IPs as a comma-separated
list. Otherwise, clients shall use the local endpoint provided by a
etcd-proxy instances on each etcd node. A Netwroking plugins always
use that access mode.
* Fix apiserver's etcd servers args to use the etcd_access_endpoint.
* Fix networking plugins flannel/calico to use the etcd_endpoint.
* Fix name env var for non masters to be set as well.
* Fix etcd_client_url was not used anywhere and other etcd_* facts
evaluation was duplicated in a few places.
* Define proxy modes only in the env file, if not a master. Del
an automatic proxy mode decisions for etcd nodes in init/unit scripts.
* Use Wants= instead of Requires= as "This is the recommended way to
hook start-up of one unit to the start-up of another unit"
* Make apiserver/calico Wants= etcd-proxy to keep it always up

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
Co-authored-by: Matthew Mosesohn <mmosesohn@mirantis.com>

Fix systemd service unit for etcd

See https://github.com/coreos/etcd/issues/4308



Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

deployment idempotent

use hyperkube coreos image

use iptables as default proxy mode

Add hostpath dynamic provisioner for PetSets

updated admission controllers for >1.2 Kubernetes

Some additional roadmap items

Defaults to false. Use with v1.3 only.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

roadmap

Change calicoctl deployment to use container

Add optional deployment mode for Docker etcd_deployment_type

Running etcd in Docker reduces the number of individual file
downloads and services running on the host.

Note: etcd container v3.0.1 moves bindir to /usr/local/bin

Fixes: #298

Add CI test matrix for GCE

Add kubelet ip

flanneld: don't redirect logs to an unreadable location

and aggregate them.

Improves upgradability of calicoctl by leveraging docker tags.

Fix kube-apiserver log level syntax

Set hyperkube version to kube_version

add documentation

upgrade to k8s v1.3.0

upgrade to etcd v3.0.1