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