Configure aggregation layer for metrics

Create initial recipes directory with metrics-server modified for
deployment in current k3s configuration.

Configure kube-apiserver, kubelets, and kube-proxy for use with
aggregation layer in order for metrics-server deployment to function
correctly.

rootless

Add extra flags for server and agent components

k8s 1.14

Add bind address server config

Change address to bind-address for scheduler and controller-manager

update docker image to new version v0.3.0

Update README for hostname req

Add information on /etc/hosts hostname requirement.

For rancher/k3s/issues/138

Signed-off-by: Thorsten Schifferdecker <schifferdecker@b1-systems.de>

Update README for airgap documentation

Add more details about using HelmChart resource

Fix installer shasum check

Airgap image checksums may accidentaly be used by the installer, be
more specific to grep only for the downloaded executable.

Update vendor

Kubelet resolv.conf DNS update

Allow the kubelet resolv-conf flag to be set, or automatically
discovered from /etc/resolv.conf & /run/systemd/resolve/resolv.conf if
no loopback devices are present, or create our own which points to
nameserver 8.8.8.8

Upgrade to golangci-lint & go v1.12.1