Use include/import tasks (#2192)

import_tasks will consume far less memory, so it should be
used whenever it is compatible.

roles/etcd/tasks/join_member.yml

@@ -10,7 +10,7 @@
     ETCDCTL_CERT_FILE: "{{ etcd_cert_dir }}/node-{{ inventory_hostname }}.pem"
     ETCDCTL_KEY_FILE: "{{ etcd_cert_dir }}/node-{{ inventory_hostname }}-key.pem"
 
-- include: refresh_config.yml
+- include_tasks: refresh_config.yml
   vars:
     etcd_peer_addresses: >-
       {% for host in groups['etcd'] -%}