Koumbit APT keyring

The old koumbit apt-key is still present in /etc/apt/trusted.gpg:

root@host236:~# apt-key list
/etc/apt/trusted.gpg
--------------------
pub   1024D/F42584E6 2008-04-06 [expired: 2012-05-15]
uid                  Lenny Stable Release Key <debian-release@lists.debian.org>

pub   4096R/55BE302B 2009-01-27 [expired: 2012-12-31]
uid                  Debian Archive Automatic Signing Key (5.0/lenny) <ftpmaster@debian.org>

pub   2048R/6D849617 2009-01-24 [expired: 2013-01-23]
uid                  Debian-Volatile Archive Automatic Signing Key (5.0/lenny)

pub   4096R/B98321F9 2010-08-07 [expires: 2017-08-05]
uid                  Squeeze Stable Release Key <debian-release@lists.debian.org>

pub   4096R/473041FA 2010-08-27 [expires: 2018-03-05]
uid                  Debian Archive Automatic Signing Key (6.0/squeeze) <ftpmaster@debian.org>

pub   1024D/1F41B907 1999-10-03
uid                  Christian Marillat <marillat@debian.org>
uid                  Christian Marillat <marillat@free.fr>
sub   1536g/C28DCC42 1999-10-03
sub   1024D/5D3877A7 2002-08-26

pub   1024D/B7C0A70A 2008-07-11 [expires: 2014-07-13]
uid                  Koumbit Debian archive autosigning <debian@debian.koumbit.net>
sub   2048g/554181B9 2008-07-11 [expires: 2014-07-13]

pub   4096R/46925553 2012-04-27 [expires: 2020-04-25]
uid                  Debian Archive Automatic Signing Key (7.0/wheezy) <ftpmaster@debian.org>

pub   4096R/65FFB764 2012-05-08 [expires: 2019-05-07]
uid                  Wheezy Stable Release Key <debian-release@lists.debian.org>

/etc/apt/trusted.gpg.d//koumbit-archive-jenkins0.gpg
----------------------------------------------------
pub   1024D/B7C0A70A 2008-07-11 [expires: 2014-07-13]
uid                  Koumbit Debian archive autosigning <debian@debian.koumbit.net>
sub   2048g/554181B9 2008-07-11 [expires: 2014-07-13]

so we have a dupe and changes to our package will not be respected. we should remove the key on postinst. i tried this:

apt-key del B7C0A70A

and it works fine - and doesn't touch our package in trusted.d.

before we do this, we need to propagate through puppet otherwise puppet will add the key back, see #14265.