Feature: support Alpine arm32v7

[LuckyTurtleDev]

It would be nice if the alpine rust docker image does also support arm32v7, how claimed by the Dockerhub readme. This would as example allow, to easily create musl docker image for the Raspberry 2 and other devices.

Probably i386 should added too, to make sure that architectures, which are claimed to be supported are actually supported.

[hwittenborn]

I'm experiencing this issue as part of a program I'm trying to package. There isn't anything stopping this from happening though, right? From what I've seen the alpine docker image supports arm32v7 (as well as upstream Rust), so I wouldn't think there'd be any technical hurdles in the way.