Add notify support to Ansible

[etoccalino]

Ansible has a concept of notify and handlers. A handler does something like restart nginx or supervisord or update apt-get or something else and is meant to run often. A task can then notify a handler with:

 - name: link nginx config
   action: file src=/etc/nginx/sites-available/${app_name}.conf dest=/etc/nginx/sites-enabled/${app_name}.conf state=link
   notify:
      - restart nginx

Unfortunately, the notifies weren't firing, so Pull Request #210 removes them and manually performs the restarts.

tl;dr: We should figure out why the notifies are not firing and fix them. My guess is something to do with the notification handlers being in different playbooks and not linked correctly.