Move kube_kubeadm_controller_extra_args to controllerManagerExtraArgs section. It was placed in controllerManagerExtraVolumes

Keep a list of checksums for kubeadm and hyperkube downloads.
Makes it easier to switch version

https://kubernetes.io/blog/2018/07/11/dynamic-kubelet-configuration/

Upstream Changes:

-   weave 2.4.1 (https://github.com/weaveworks/weave/releases/tag/v2.4.1)

Our Changes:

-   Templates sync with upstream manifests

Upstream Changes:

-   cert-manager 0.5.0 (https://github.com/jetstack/cert-manager/releases/tag/v0.5.0)

Our Changes:

-   Templates sync with upstream manifests

Uses correct flag for draining with a pod selector
Verifies minimum kubectl version for compatibility

This commit fixes #3295

Optionally do not drain nodes by setting drain_nodes to false
Optionally set a labelselector to target which pods should be drained.

When enable_network_policy is set to True with Calico 3 kubectl
apply fails with the error:

The Deployment "calico-kube-controllers" is invalid:
spec.strategy.rollingUpdate: Forbidden: may not be specified when
strategy type is 'Recreate'

See

https://github.com/kubernetes-incubator/kubespray/issues/3267

Changing the update strategy to RollingUpdate avoids this error.