fix amp issue for lucidrains#82

numerical accuracy for noise schedule parameters

wrap up cross embed layer feature

bring in the cross embed layer from Crossformer paper for initial con…

…volution in unet

make sure cascading DDPM can be trained unconditionally, to ready for…

… CLI one command training for the public

fix new issue with github actions and auto pypi package uploading

make sure resnet groups in unet is finely customizable

patch

Ensure Eval Mode In Metric Functions (lucidrains#79)

* add eval/train toggles

* train/eval flags

* shift train toggle

Co-authored-by: nousr <[email protected]>