pyrocufflink: Ensure winbind is running

Since the first pass of `pyrocufflink.yml` always fails to start the
*winbind* service (since the machine is not yet a member of the domain),
a second pass is required to start it. It can't be started as part of
the *winbind* role, though, since it would fail. As such, it has to be
started at the very end of the play.

pyrocufflink.yml

@@ -3,3 +3,8 @@
   - winbind
   - nsswitch
   - system-auth
+  tasks:
+  - name: ensure winbind is running
+    service:
+      name=winbind
+      state=started