We currently only invalidate the cache if the Debian repository changes,
but not if the CentOS repository changes. This leads to strange
artefacts, such as CentOS containers for osmo-bts-master using an
old libosmocore, despite a new one being available in the repo.
As Dockerfiles don't support conditional "ADD", we need to actually
add both the CentOS and the Debian repsotiry file, so any change
in either of the two will now (unneccessarily) invalidate the cache
for both Debian and CentOS builds.
Change-Id: I7b13644afb9d3be3b94184193177e003c13718d3
Adjust the Dockerfiles, so 'docker_images_require osmo-mgw-master-centos8'
etc. result in a centos8 based image. centos8-build already configures the
Osmocom nightly repository, so we only need to configure it for
debian-stretch.
Related: OS#4564
Change-Id: I6579748056ce0505304378b342a698b98c77fd18
This way we can run the container with osmo-remsim-bankd + ifd-vpcd,
i.e. with a simulated smart card reader behind the bank.
Change-Id: I463eca0f66197b409e00028e75e9501de620cc8b