I switching to use only one ssh key (luke_chronos_key).

We know that on Debian 9 used version of ansible does not work with success,
so let's make the "when" part depending on the distribution.

/reviewed-on !108

  Since the upgrade isn't perfectly stable, don't upgrade the package anymore.

/cc @jerome @jm  (You were asking about this)

/reviewed-on nexedi/slapos.package!105

Ces images on été construite pour Teralab.
 La Ubuntu18 a été testée, la debian10 non.
Les fichiers de preseed et les bootcommande font des opérations redondantes.

This reverts commit 0e51aaef.

The latest tag wasn't compiling fine because of erp5-doc still being a
submodule in erp5-vifib branch but not in slapos anymore.

For now nofile hard limit is set to 1048576.

/reviewed-on !104

slapos node collect needs them to query hardware status.

/reviewed-on nexedi/slapos.package!103

The kernel in Debian9 was updated by upstream and new updates, among
regular bugfixes contain fixes for security issues:

https://metadata.ftp-master.debian.org/changelogs//main/l/linux/linux_4.9.189-3_changelog

The kernel was also included into just oldstable (compared to
oldstable-proposed-updates). I'm not dropping oldstable-proposed-updates
repository for now, since maybe we might need it once again in the
future.

/reviewed-on !102

@rafael  or @tomo 

Please feel free to merge in so we can have deployment tests working back again.

/reviewed-on !101

  fuse requires to be system wide installed, as it is linked with kernel modules.

  Only 4.9.185 contains the fix from Kiril. For now, debian 8 won't contains it.

  The user can decide set upgrade kernel as True, by doing so, the computer will start
  to automatically upgrade kernel on the next upgrades.

  The invokation of the script is done manually, in future we might have a cron task

   Officially we prefer erp5.net for now.

  We may keep some legacy distros arround for a while, but I'm not sure it can run fully.

  This is too old we may not want to support it anymore