The k8s external-dns project now uses the official Kubernetes projects
container registry at k8s.gcr.io. Update all references to use the new
registry.

The extensions/v1beta1 API is deprecated for Deployment and with 1.16 is
not served by default anymore. This breaks the examples on k8s 1.16.

See this blog post for details on the deprecations:

https://kubernetes.io/blog/2019/07/18/api-deprecations-in-1-16/

* Add recent changes to the changelog
* Update version in docs
Signed-off-by: Nick Jüttner <nick@zalando.de>

* add "dyn" provider
* add several --dyn-* args to configure Dyn login
* add github.com/nesv/go-dynect/dynect@0.6.0 to Gopkg and vender/ (the client
  of choice by Terraform)
* make externdns.Version public so it can be stored when committing
  zone changes
* add tutorial for Ingress resources and update root README.md file

Dyn REST API is documented here: https://help.dyn.com/dns-api-knowledge-base/

Example usage:

  external-dns \
    --provider=dyn \
    --dyn-customer-name=acme \
    --dyn-username=acme-api \
    --dyn-password=t0pS3cr3t \
    --domain-filter=portal.acme.com \
    --zone-id-filter=acme.com \
    --namespace=my-test-ns \
    --log-level=debug \
    --txt-prefix=_