dependencies:
   - { role: ejabberd_xs, tags: ['olpc','ejabberd-xs','xo-services'], when: ejabberd_xs_install }
   - { role: idmgr,  tags: ['olpc','idmgr','xo-services'], when: idmgr_install }
   - { role: activity-server, tags: ['olpc','activity-server','xo-services'], when: activity_server_install }