The get_root_logger(log_file=None, log_level=logging.INFO) function does not needs the string type cfg.log_level as input. This bug does not have negative effect.
* add mytrain.py for test
* test before layers
* test attr in layers
* test classifier
* delete mytrain.py
* register custom_hooks in runner
* set custom_hooks_config to cfg.get(custom_hooks, None)
* Use build_runner in train api
* Support iter in eval_hook
* Add runner section
* Add test_eval_hook
* Pin mmcv version in install docs
* Replace max_iters with max_epochs
* Set by_epoch=True as default
* Remove trailing space
* Replace DeprecationWarning with UserWarning
* pre-commit
* Fix tests