Don't fail when pulling previous build image fails (eg: image does not exist).

7 jobs for <span class="ref-name">rename</span> in 12 minutes and 24 seconds
Status Job ID Name Coverage
  Test Build
failed #45665070
build_test

00:00:29

passed #45665011
check

00:02:07

passed #45665015
codequality

00:12:21

passed #45665013
dataset

00:01:14

passed #45665012
integration

00:04:38

passed #45665010
test

00:03:01

45.0%
failed #45665014
build_test

00:00:30

 
Name Stage Failure
failed
build_test Test Build There is an unknown failure, please try again
(1/1) Installing curl (7.57.0-r0)
Executing busybox-1.26.2-r9.trigger
OK: 28 MiB in 20 packages
$ docker login -u gitlab-ci-token -p $CI_BUILD_TOKEN registry.gitlab.com
WARNING! Using --password via the CLI is insecure. Use --password-stdin.
Login Succeeded
$ docker pull registry.gitlab.com/failmap/failmap:latest
Error response from daemon: manifest for registry.gitlab.com/failmap/failmap:latest not found
ERROR: Job failed: exit code 1