Fix SELinux permissive mode detection logic

- add selinux fix right after installing docker package on centos
- prevent setenforce failure
- set selinux permissive only when it needs to be
- fix selinux permissive check

[WKP-142] Add rhel support

integration tests - preemptible, no restarts, self-destruct in 48h

add a new case statement for rhel

small changes

cleanups

apply pr review changes

add rhel integration test

enable rhel integration test

enable USE_IMAGE=1 for rhel

fix centos test incorrectly running ubuntu

Install Sealed Secrets CRD before controller

Signed-off-by: Dinos Kousidis <dinos@weave.works>

Updates sealed secret controller manifest to v0.11.0

Signed-off-by: Dinos Kousidis <dinos@weave.works>

* Added a complete description of the apply command

added wksctl apply --help + flags

* added ```console```

* moved ```console above wksctl apply --help

move to mkdocs

Adds eksctl functions to write and merge kubeconfig files

* Switches context to newly created cluster by default, except if
  if --use-context=false is passed.

* If --artifact-directory is not passed, and ~/.kube/config file
  exists, the context is merged in the existing file. If ~/.kube/config
  doesn't exist, it creates it.

* Sets SilenceUsage to true in kubeconfig root command, to avoid showing
  the usage message in the case of error.
  Relevant issue: https://github.com/spf13/cobra/issues/340

* Removes printing of error in Execute() of kubeconfig command
  to avoid printing twice an error message.
  Relevant issue: https://github.com/spf13/cobra/issues/304



* Updates docs in `wksctl kubeconfig` part
Signed-off-by: Dinos Kousidis <dinos@weave.works>

Fixes #146 

* add --control-plane-endpoint to kubeadm init and use it for join cmd

* make kubeadm join to aware of externalLoadBalancer

* re-fix control-plane-endpoint

* Add the call to kubeadm init back in for the intial machine

* Fall back to first master when no original can be found by matching addresses

* add kubeadm 1.16 support by removing the control-plane argument

* use a proper control-plane flag for 1.14.x, and make it compat with 1.15.x, 1.16.x

* introduce original-master label and fix upgrade flag to support both 1.15 and 1.16

 - introduce original-master label
 - fix to not marking original-master label to every master node
 - fix 2nd masters upgrade flag to support both 1.15 and 1.16
 - remove plan hide from the externalLoadBalancer field

* show plan diff when two plans were compared during node update

* improve comment

* change prefix of constants

* use Errorf instaead of Infof

* reverted change of performActualUpdate

* move originalMaster labeling into its method, getOriginalMasterNode
Co-authored-by: Mark Emeis <palemtnrider@gmail.com>
Co-authored-by: weave-e2e-quickstart <58864910+weave-e2e-quickstart@users.noreply.github.com>
Co-authored-by: Mahmoud Saada <mahmoudsaada@gmail.com>

* Update serve docs url

* update copyright year

* Update footloose instructions.

* Fix grammar and new firekube page

* Add firekube page to the index

* Fix typo on Firekube instructions
Co-Authored-By: Kingdon Barrett <kbarret8@nd.edu>

* Update make serve-docs URL.
Co-Authored-By: Dimitri Mitropoulos <dimitrimitropoulos@gmail.com>
Co-authored-by: Kingdon Barrett <kbarret8@nd.edu>
Co-authored-by: Dimitri Mitropoulos <dimitrimitropoulos@gmail.com>

* Remove Damien and Michal add Bryan and Chanwit

Co-authored-by: giannicarabelli <59476365+giannicarabelli@users.noreply.github.com>
Co-authored-by: Mark Emeis <palemtnrider@gmail.com>