Refactor etcd role

- Run docker run from script rather than directly from systemd target
- Refactoring styling/templates

Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

roles/etcd/tasks/refresh_config.yml

@@ -1,7 +1,7 @@
 ---
 - name: Refresh config | Create etcd config file
   template:
-    src: etcd.j2
+    src: etcd.env.yml
     dest: /etc/etcd.env
   notify: restart etcd
   when: is_etcd_master