add unbuffer and ts for timestamping to artful image

7 jobs for master in 7 minutes and 42 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
passed #24384
docker-in-docker
build_artful_amd64

00:07:40

passed #24382
docker-in-docker
build_buster_amd64

00:00:53

passed #24379
docker-in-docker
build_jessie_amd64

00:00:49

passed #24381
docker-in-docker
build_sid_amd64

00:00:54

passed #24380
docker-in-docker
build_stretch_amd64

00:00:53

passed #24383
docker-in-docker
build_zesty_amd64

00:00:53

passed #24385
docker-in-docker
test_jessie_amd64

00:00:53