[Debian-med-packaging] ariba is marked for autoremoval from testing

[Debian testing autoremoval watch]

ariba 2.13.1+ds-1 is marked for autoremoval from testing on 2018-12-31

It (build-)depends on packages with these RC bugs:
911492: htslib, src:python-pysam: htslib breaks python-pysam autopkgtest