Force docker format when committing container images

See freedesktop/freedesktop#178 (comment 201897)

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
29 jobs for wip/cleanups in 33 minutes and 17 seconds (queued for 4 minutes and 54 seconds)
Status Job ID Name Coverage
  Bootstrapping
passed #475444
bootstrap

00:04:17

 
  Arch Container Build
passed #475445
arch@container-build

00:02:02

passed #475446
arch-forced@container-ifnot-exists

00:01:44

 
  Arch Check
passed #475447
arch@check

00:00:32

passed #475449
arch@container-ifnot-exists

00:00:32

passed #475448
arch-forced-ifnot-exists@check

00:00:21

 
  Ubuntu Container Build
passed #475452
ubuntu:18.04@container-build

00:01:12

passed #475450
ubuntu:18.10@container-build

00:01:22

passed #475451
ubuntu-forced:18.10@container-ifnot-exists

00:01:22

 
  Ubuntu Check
passed #475456
ubuntu:18.04@check

00:00:44

passed #475453
ubuntu:18.10@check

00:00:31

passed #475455
ubuntu:18.10@container-ifnot-exists

00:00:36

passed #475454
ubuntu:forced-ifnot-exists@check

00:00:30

 
  Debian Container Build
passed #475459
debian:buster@container-build

00:01:40

passed #475458
debian-forced:stretch@container-ifnot-exists

00:01:28

passed #475457
debian:stretch@container-build

00:01:32

 
  Debian Check
passed #475463
debian:buster@check

00:00:41

passed #475461
debian:forced-ifnot-exists@check

00:00:18

passed #475460
debian:stretch@check

00:00:23

passed #475462
debian:stretch@container-ifnot-exists

00:00:37

 
  Fedora Container Build
passed #475464
fedora:29@container-build

00:03:41

passed #475466
fedora-forced:rawhide@container-ifnot-exists

00:02:14

passed #475465
fedora:rawhide@container-build

00:02:33

 
  Fedora Check
passed #475467
fedora:29@check

00:00:22

passed #475471
fedora:29-upstream@container-ifnot-exists

00:00:23

passed #475469
fedora-forced-ifnot-exists:rawhide@check

00:00:18

passed #475468
fedora:rawhide@check

00:00:18

passed #475470
fedora:rawhide@container-ifnot-exists

00:00:20

 
  Container Push
passed #475472
bootstrap-push@push

00:00:31