Fastxtend

Adds the Lion Optimizer

**Full Changelog**: https://github.com/warner-benjamin/fastxtend/compare/v0.0.17...v0.0.18

Decrease Adan memory usage and increase optimizer step speed
Fix EMA callbacks not applying to buffers
EMA callback accepts epochs or percent of total training

**Full Changelog**: https://github.com/warner-benjamin/fastxtend/compare/v0.0.15...v0.0.16

Drop support for Python 3.7. CI tests on Python 3.8, 3.9, & 3.10.

ProgressiveResize can be imported independent of other fastxtend features.

Bug fixes

**Full Changelog**: https://github.com/warner-benjamin/fastxtend/compare/v0.0.14...v0.0.15

0.2-0.25x speed improvement to EMACallback

v.0.0.13
Updated `EMACallback` and `EMAWarmupCallback` with new features, including a fast fused implementation, EMA start delay, and EMA warmup.

Added two new schedulers: `fit_flat_warmup` and `fit_cos_anneal`.

Bug fixes.

**Full Changelog**: https://github.com/warner-benjamin/fastxtend/compare/v0.0.12...v.0.0.13