Split Vagrantfile Ubuntu versions into 1604 and 1804 (#3440)

https://github.com/kubernetes/kubernetes/issues/69214

- Local Volume StorageClass configuration is now manged by `local_volume_provisioner_storage_classes`, a list of maps that specifies local storage classes with `name` `host_dir` and `mount_dir` keys per entry
- Tasks and templates updated to loop through local volume storage classes
- Previous defaults for path/class names were not changed
- Fixed an issue where a `kubernetes/preinstall` was creating directories inconsistently with the `kubernetes-apps/external_provisioner/local_volume_provisioner` task

* Upgrade kubernetes to v1.12.0

Use kubeadm v1alpha3 config

* Upgrade coredns and etcd

* Upgrage docker to 18.06

Add note to README about offline environments

Internet access is not mandatory as long as the user configures all container image repositories to point to internal container registries, in case of on-premises installation with firewall rules preventing direct Internet access.

* Fix the jinja expression for openstack_tenant_id

OS_PROJECT_ID is obsolete in keystone v3 and jinja expression
doesn't set openstack_tenant_id as expected because of
undefined env var. Fixed the expression.

* Fix the dic iteration method in the kubelet template

Kubelet template rendering errors when additional Node lables are
added and using Python3. Update the method to be compatible to both
python2/3

Node lables doesn't work

According to the documentation, container images are described
by vars like `foo_image_repo` and `foo_image_tag`.
The variables netcheck_{agent,server}_{img_repo,tag} do not
follow that convention.

* Replace `openstack_compute_secgroup_v2` with `openstack_networking_secgroup_v2`

The `openstack_networking_secgroup_v2` resource allow specifications of
both ingress and egress. Nova security groups define ingress rules only.

This change will also allow for more user-friendly specified security
rules, as the different security group resources have different HCL
syntax.

* Better fix for openstack cinder zone issue[1][2]
using ignore-volume-az option[3].
[1]: https://github.com/kubernetes-incubator/kubespray/pull/2155
[2]: https://github.com/kubernetes-incubator/kubespray/pull/2346
[3]: https://github.com/kubernetes/kubernetes/pull/53523

* Remove kube-scheduler-policy.yaml

Before, Nodes tainted with NoExecute policy did not have calico/weave Pod.
Network pod should run on all nodes whatever happens on a specific node.

Also always set the Pods to be critical.
Also remove deprecated scheduler.alpha.kubernetes.io/tolerations annotations.

* fixes: #3387

* Change execution order for pip

* Remove spaces

to fix the follow problem in case quote is not used:

PLAY [k8s-cluster:etcd:calico-rr] **********************************************
ERROR! Syntax Error while loading YAML.
  expected <block end>, but found '<scalar>'

The error appears to have been in '/tmp/vagrant-ansible/inventory/group_vars/k8s-cluster.yml': line 59, column 39, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

kube_oidc_ca_file: {{ kube_cert_dir }}/openid-ca.pem
                                      ^ here
We could be wrong, but this one looks like it might be an issue with
missing quotes.  Always quote template expression brackets when they
start a value. For instance:

    with_items:
      - {{ foo }}

Should be written as:

    with_items:
      - "{{ foo }}"

Ansible failed to complete successfully. Any error output should be
visible above. Please fix these errors and try again.

* Changes to assign pod priority to kube components.

* Removed the boolean flag pod_priority_assignment

* Created new priorityclass k8s-cluster-critical

* Created new priorityclass k8s-cluster-critical

* Fixed the trailing spaces

* Fixed the trailing spaces

* Added kube version check while creating Priority Class k8s-cluster-critical

* Moved k8s-cluster-critical.yml

* Moved k8s-cluster-critical.yml to kube_config_dir

Signed-off-by: Rui Cao <ruicao@alauda.io>