Keep zookeeper enabled

Without this, the service seems to just loop failing to start
indefinitely even though PVC attempts to start the daemon itself.
Reenabling seems to work. Likely a bug due to Zookeeper not being
a proper systemd unit.

roles/pvc/tasks/zookeeper/main.yml

@@ -18,11 +18,11 @@
     - zoo.cfg
   notify: restart zookeeper
 
-- name: start but disable services
+- name: start and enable services
   service:
     name: "{{ item }}"
     state: started
-    enabled: no
+    enabled: yes
   with_items:
     - zookeeper