Reducing crate_universe lockfile size?

Hi all,

I finally had a chance to experiment properly with crate_universe, and it looks like it'll be a nice improvement over having to commit the BUILD files manually and manually list out dependencies - crates_from() is great!

One thing I noticed is that the lockfile is considerably bigger than Cargo's - in the modest workspace I'm testing with, Cargo's is about 100k, and the universe one is around 1.8MB. When updating dependencies, the changed lines in git appear to be approximately 10x what they are in the Cargo.lock file.

Would it be practical to store the locked versions in a more compact format in the future?