Add playbook and role to reset the cluster

This deletes everything related to the cluster and allows to start from
scratch.

reset.yml

+---
+
+- hosts: all
+  roles:
+    - { role: reset, tags: reset }

roles/reset/tasks/main.yml

+---
+
+- name: reset | stop services
+  service: name={{item}} state=stopped
+  with_items:
+    - kubelet
+    - etcd
+  failed_when: false
+
+- name: reset | remove services
+  file: path="/etc/systemd/system/{{item}}" state=absent
+  with_items:
+    - kubelet
+    - etcd
+  register: services_removed
+
+- name: reset | systemctl daemon-reload
+  command: systemctl daemon-reload
+  when: ansible_service_mgr == "systemd" and services_removed.changed
+
+- name: reset | remove all containers
+  shell: docker ps -aq | xargs -r docker rm -fv
+
+- name: reset | gather mounted kubelet dirs
+  shell: mount | grep /var/lib/kubelet | awk '{print $3}'
+  register: mounted_dirs
+
+- name: reset | unmount kubelet dirs
+  command: umount {{item}}
+  with_items: '{{mounted_dirs.stdout_lines}}'
+
+- name: reset | delete some files and directories
+  file: path={{ item }} state=absent
+  with_items:
+    - /etc/kubernetes/
+    - /var/lib/kubelet
+    - /var/lib/etcd
+