Chronumental

Fixes the use of GPU

Clarifies branch_len gth_ ariance parameter, and relaxes this prior

What's Changed
No longer requires pinned Numpyro ver

What's Changed
* Switch from tqdm to alive progress by theosanderson in https://github.com/theosanderson/chronumental/pull/19


**Full Changelog**: https://github.com/theosanderson/chronumental/compare/v0.0.49...v0.0.50

- Allows forcing the reference node to be a particular node

What's Changed
* Remove a memory bottleneck caused by lists instead of arrays during sparse matrix construction by theosanderson in https://github.com/theosanderson/chronumental/pull/17


**Full Changelog**: https://github.com/theosanderson/chronumental/compare/v0.0.47...v0.0.48