special deployement needed for this:
------------------------------------
 * stop workers  # FIXME -command?
 $ sudo -u jenkins /srv/jenkins/bin/reproducible_cleanup_nodes.sh
 $ sudo -u jenkins /srv/jenkins/bin/reproducible_cleanup_nodes.sh
 * https://jenkins.debian.net/quietDown
 $ cd ~jenkins-adm/jenkins.debian.net
 $ sudo update_jdn.sh
 $ sudo -u jenkins -i
 // as jenkins user:
 $ cd /var/lib/jenkins/userContent/reproducible/debian
 $ for i in issues logs rb-pkg logdiffs buildinfo dbdtxt rbuild dbd ; do
     mv $i/testing $i/stretch
   done
 $ mv testing stretch
 $ cd /srv/reproducible-results
 // job will take care of recreating this one appropriately, won't it?
 $ rm -rf --one-file-system meta_pkgsets-testing chdist-testing
 $ /srv/jenkins/bin/reproducible_db_maintenance.py
 $ exit
 * https://jenkins.debian.net/cancelQuietDown
 $ cd ~jenkins-adm/jenkins.debian.net
 $ sudo update_jdn.sh
 * remove all jobs which match reproducible*testing*
 // hit all new jobs (to create chroots, etc) in:
 * https://jenkins.debian.net/view/reproducible/view/Debian_setup_amd64/
 * https://jenkins.debian.net/view/reproducible/view/Debian_setup_arm64/
 * https://jenkins.debian.net/view/reproducible/view/Debian_setup_armhf/
 * https://jenkins.debian.net/view/reproducible/view/Debian_setup_i386/
 * restart workers  # FIXME -command?

changes not yet prepared in git
-------------------------------
db changes
prepare to add buster on 2017-06-17
(including changing the apache redirect testing→stretch to testing→buster)
finally, remove this file again.