[devtools] properly close open access on tearDown avoiding further warning about living sessions while the repo is turned off. The doc string says: The RepoAccess need to be closed to destroy the associated Session. TestCase usually take care of this aspect for the user. but that wasn't true until now.

etc/init.d
etc/cubicweb.d
etc/bash_completion.d
usr/bin
usr/share/doc/cubicweb-ctl
var/log/cubicweb
var/lib/cubicweb/backup
var/lib/cubicweb/instances