* Make name and version properties required
* Warn before deleting files in checkpoint directory
* Get default checkpoint path from any logger
* Fix typos
* Uncomment logger tests
* Whitespace
* Update callback_config_mixin.py
checkpoints and version file names would just have a number. it's easy to tell what you're looking at with version_ prepended
* Address comments
* Fix broken tests
* moved dp, ddp outside of trainer
* added main mixins
* finished major mixin refactor
* flake8
* finished major mixin refactor
* finished major mixin refactor
* finished major mixin refactor
* finished major mixin refactor
* finished major mixin refactor
* finished major mixin refactor
* finished major mixin refactor