In our APBs, in some cases there's more than one place where an image name:version is defined. E.g. here: https://github.com/aerogearcatalog/unifiedpush-apb/search?q=docker.io&unscoped_q=docker.io

This is usually under metadata.dependencies in the apb.yml, and then also in vars in playbooks.

We should either just have one place where the name:version is defined (probably this), or else have a scripted way to update each image that's defined in an APB.

We'll be changing the image name and version downstream, and if it can be listed in an arbitrary number of places, then it'll be difficult to do that in an automated way.