Add optional deployment mode for Docker etcd_deployment_type

Running etcd in Docker reduces the number of individual file
downloads and services running on the host.

Note: etcd container v3.0.1 moves bindir to /usr/local/bin

Fixes: #298

roles/etcd/handlers/main.yml

@@ -3,13 +3,20 @@
   command: /bin/true
   notify:
     - reload systemd
+    - start etcd
     - reload etcd
 
 - name: reload systemd
   command: systemctl daemon-reload
   when: ansible_service_mgr == "systemd"
 
+- name: start etcd
+  service:
+    name: etcd
+    enabled: yes
+    state: started
+
 - name: reload etcd
   service:
     name: etcd
-    state: restarted
+    state: "{{ 'restarted' if etcd_deployment_type == 'host' else 'reloaded' }}"