Upgrade to golangci-lint & go v1.12.1

Add tls-san flag

Skip writing manifest when using `--no-deploy`

Re-enable build validation

Instead of skipping the manifest when listing the directory, we now skip
creating it in the first place. This allows users to deploy manifests
that replaces the ones bundled, without having to come up with a new
name.

Fixes #230.

Adjust the startup order of docker-compose

Fix go get golang.org/x/* packages timed out issue.

* Set the selinux context

Generate air-gap image artifacts

Generate airgap artifacts from an images list for each architecture.

PullAlways ImagePullPolicy causes issues with offline/airgap support,
so only pull if image is not already present.

Fix version for cli

Air-gap chart support

Include static Helm assets in the build process needed for air-gap

Update docker-compose for v0.2.0, add agent docker-compose, update re…

Provide a static assets route for use with helm or other air-gap needs.

Change-Id: I60c92d0127cfc503c46b26fe7b2e3ad2f957dfa3

In NAT or LB environment,
we need not just the certs for local ip, but also additional ips.
advertise-address flag enables to add optional ips.

Update README for correct VXLAN port

fix typo

Do not process empty yaml objects (fixes #222)

Short port names for service load balancer

If a port name is longer than 15 characters we are unable to create
the associated service load balancer containers. Use our own short
name of `lb-port-{port}` to avoid naming issues.

For rancher/k3s/issues/90

k3s agent param `-u` is incorrect, use `-s`

Update docker-compose for v0.2.0, add agent docker-compose, update readme for docker agent run command