ci: packer cache script should fail never to help to cache dependencies

[v1v]

Closed #805

Highlights

• The responsibility to validate the build should not be addressed within the packer cache script.
• This will help to fetch and cache all the maven dependencies and also the docker images independently of the maven build status.
• -Dmaven.test.failure.ignore=true could be an option but I'd rather prefer to avoid failing the maven build instead.

[felixbarny]

+1 for -Dmaven.test.failure.ignore=true

[mdelapenya]

LGTM 👍

[v1v]

I'd rather say -Dmaven.test.failure.ignore=true will be more prescriptive in the hypothetical case the master branch got a compilation error, when it should not happen, and therefore this script will fail. That's the main reason for using fail-never instead. What do you think @felixbarny ?

[felixbarny]

I misunderstood the meaning of --never-fail. I thought it would behave as normal but always exit with exit code 0. But it seems like it continues when tests fail 👍