Combine commands when applicable

Thanks for being awesome about keeping this up to date! I noticed during a fresh build the other day that there are a *lot* of layers coming out of this base image, so this is a PR to help clean that up a little. All I've done is combine run commands when applicable, which should have a few side affects.

- Meaningful build cache
- Fewer FS layers

All in all, this takes a build from 32 steps to 18 while still staying fairly readable (imo).