Make zprint version configurable

[mitchelkuijpers]

We want to use boot-fmt but we need some features from a newer zprint, Would it be an idea to give the version of print as a option to boot-fmt? This would not make it necessary to cut a new release each time a new zprint get's released.

[pesterhazy]

An interesting idea. Is there a precedent, a project that allows you to parametrize dependencies? It's easy to do because we use pods, but I'm not 100% sure if it's a good idea.

In the meantime I've updated boot-fmt to zprint 0.3.1, thanks for the reminder.

[madstap]

In lieu of a configurable version, it would be great if you could bump zprint again. 0.4.10 has some important bugfixes.