* using separated vault roles for generate certs with different `O` (Organization) subject field;
* configure vault roles for issuing certificates with different `CN` (Common name) subject field;
* set `CN` and `O` to `kubernetes` and `etcd` certificates;
* vault/defaults vars definition was simplified;
* vault dirs variables defined in kubernetes-defaults foles for using
shared tasks in etcd and kubernetes/secrets roles;
* upgrade vault to 0.8.1;
* generate random vault user password for each role by default;
* fix `serial` file name for vault certs;
* move vault auth request to issue_cert tasks;
* enable `RBAC` in vault CI;
* Added update CA trust step for etcd and kube/secrets roles
* Added load_balancer_domain_name to certificate alt names if defined. Reset CA's in RedHat os.
* Rename kube-cluster-ca.crt to vault-ca.crt, we need separated CA`s for vault, etcd and kube.
* Vault role refactoring, remove optional cert vault auth because not not used and worked. Create separate CA`s fro vault and etcd.
* Fixed different certificates set for vault cert_managment
* Update doc/vault.md
* Fixed condition create vault CA, wrong group
* Fixed missing etcd_cert_path mount for rkt deployment type. Distribute vault roles for all vault hosts
* Removed wrong when condition in create etcd role vault tasks.
