Add library/ prefix for image name

[vanta]

Ideally, such a change should be done to the 1.x release, as with the version 2.x, there is a way to pass a DockerImageName instance.

[eddumelendez]

This should work already without changes. Thanks anyway.

[vanta]

@eddumelendez It's not working in our case - we have the ECR as a proxy to Docker Hub, and ECR cannot do it with _. It's a small change and should not harm.

Any chance to push it to 1.x release?

[eddumelendez]

1.x is not released anymore