Bug#884699: lintian: please bump recommended debhelper compat to 11

[Niels Thykier <niels@thykier.net>]

Chris Lamb:
> tags 884699 + pending
> thanks
> 
> Fixed in Git:
> 
>   https://anonscm.debian.org/git/lintian/lintian.git/commit/?id=8c7cbd27c1255d01c21a78e1ead89fe500c94201
> 
> 
> Regards,
> 

Looks like several of the tests break because debhelper is now breaking
the builds in stretch.  We should probably ensure that debhelper/10.10.9
or later is used.

This means:
 * Jenkins need to use backports for stretch
 * We will have to drop the jessie job on Jenkins (being oldstable it is
   not in our target supported releases).
 * A B-D on debhelper (>= 10.10.9~) in d/control should take care of the
   lintian side of things once the above is handled.

Thanks,
~Niels