ansible/docker: set overlayfs2 and ipv6

overlayfs2 should be the default anyway. Enable it on all hosts,
since it was enabled on older hosts.

Change-Id: I20728d6017204c3978e23376baa89de6e91fed1e

ansible/roles/docker/files/daemon.json

@@ -0,0 +1,5 @@
+{
+  "ipv6": true,
+  "storage-driver": "overlay2",
+  "fixed-cidr-v6": "fd02:db8:1::/64"
+}

ansible/roles/docker/handlers/main.yml

@@ -0,0 +1,6 @@
+---
+
+- name: restart docker
+  service:
+    name: docker
+    state: restarted

ansible/roles/docker/tasks/main.yml

@@ -38,3 +38,9 @@
     hour: '*/3'
     user: "{{ jenkins_user }}"
     job: "test -x /home/{{ jenkins_user }}/osmo-ci/scripts/docker-cleanup.sh && /home/{{ jenkins_user }}/osmo-ci/scripts/docker-cleanup.sh >/dev/null"
+
+- name: copy daemon.json to support ipv6
+  copy:
+    src: daemon.json
+    dest: /etc/docker/daemon.json
+  notify: restart docker