ruby-dbi is not shipped anymore in Debian (-> jessie).

As a result, OAR was removed from Debian testing.

TODO for 2.5.4
  * remove drawgantt v1 from the packaging
  * remove oaradmin from the packaging
  * write a new script to handle admission rules, in Perl.

A new script to handle the resources like oaradmin does could be rewritten later (not for 2.5.4).