fix typo

[contrib/terraform/openstack] Add support for router less deployments

Add bin_dir to kubectl version check

Upstream Changes:

-   ingress-nginx 0.20.0 (https://github.com/kubernetes/ingress-nginx/releases/tag/nginx-0.20.0)

Our Changes:

-   Sync templates with upstream changes

kubeadm sets node label node-role.kubernetes.io/master=''
and this is not configurable. We should use it everywhere.

Fix typo

* codestyle tests

* Download destination can be different than local_release_dir

Fix missing s in link to kube-router docs

[contrib/terraform/openstack] Add list of know working OpenStack clouds

kube-router v0.2.1 highlights from changelog:
- IPv6 WIP but pretty close to full working functionality
- fully support network policy semantics with addition of support for
  ipblock and except

* warning on meta flush_handlers

* avoid rm

* avoid "Module remote_tmp /root/.ansible/tmp did not exist and was created with a mode of 0700, this may cause issues when running as another user. To avoid this, create the remote_tmp dir with the correct permissions manually" warning on subsequent tasks using blockinfile

* is match

 [jjo] improve contrib/dind/run-test-distros.sh via spec files

* failed

* version_compare

* succeeded

* skipped

* success

* version_compare becomes version since ansible 2.5

* ansible minimal version updated in doc and spec

* last version_compare

* [jjo] add kube-router support

Fixes cloudnativelabs/kube-router#147.

* add kube-router as another network_plugin choice
* support most used kube-router flags via
  `kube_router_foo` vars as other plugins
* implement replacing kube-proxy (--run-service-proxy=true) via
  `kube_proxy_mode: none`, verified in a _non kubeadm_enabled_
  install, should also work for recent kubeadm releases via
  `skipKubeProxyInstall: true` config

* [jjo] address PR#3339 review from @woopstar

* add busybox image used by kube-router to downloads

* fix busybox download groups key

* rework kubeadm_enabled + kube_router_run_service_proxy

- verify it working ok w/the kubeadm_enabled and
  kube_router_run_service_proxy true or false

- introduce `kube_proxy_remove` fact, to decouple logic
  from kube_proxy_mode (which affects kubeadm configmap
  settings, thus no-good to ab-use it to 'none')

* improve kube-router.md re: kubeadm_enabled and kube_router_run_service_proxy

* address @woopstar latest review

* add inventory/sample/group_vars/k8s-cluster/k8s-net-kube-router.yml

* fix kube_router_run_service_proxy conditional for kube-proxy removal

* fix kube_proxy_remove fact (w/ |bool), add some needed kube-proxy tags on my and existing changes

* update kube-router tolerations for 1.12 compatibility

* add PriorityClass to kube-router DaemonSet

The hosts(5) manpage clearly states that the first entry is the
"canonical name", or FQDN (Fully-Qualified Domain Name):

    IP_address canonical_hostname [aliases...]

By using the alias as a first entry, `hostname -f` does not return the
correct domain which breaks all sorts of unrelated functionality (it
has impact over email server configuration, for example).