contrib/ansible: Add reset role and playbook to reset a node (#1565)

contrib/ansible/reset.yml

+---
+
+- hosts: k3s-cluster
+  gather_facts: yes
+  become: yes
+  roles:
+    - { role: reset }

contrib/ansible/roles/reset/tasks/main.yml

+---
+- name: Disable services
+  systemd:
+    name: "{{ item }}"
+    state: stopped
+    enabled: no
+  with_items:
+    - k3s
+    - k3s-node
+
+- name: Remove service files, binaries and data
+  file:
+    name: "{{ item }}"
+    state: absent
+  with_items:
+    - "{{ systemd_dir }}/k3s.service"
+    - "{{ systemd_dir }}/k3s-node.service"
+    - /etc/rancher/k3s
+    - /var/lib/rancher/k3s
+    - /var/lib/kubelet
+    - /usr/local/bin/k3s
+
+- name: daemon_reload
+  systemd:
+    daemon_reload: yes