GitLab

* add isort config

* use isort to sort imports

* add isort to travis

* Fix license in setup.py

* Add code for loss evaluator

* Configs support loss evaluator

* Fix a little bug

* Fix flake8

* return revised bbox to reg

* return revised bbox to reg

* revision according to comments

* fix flake8

* use_sigmoid_cls -> cls_sigmoid_loss; use_focal_loss -> cls_focal_loss

* fix flake8 error

* cls_sigmoid_loss - > use_sigmoid_cls

* rename normalize to norm_cfg

* update configs

* Update resnet.py

* support GN in RetinaHead

* add conv_cfg argument for RetinaHead

* add model upgrading tool and update retinanet model urls

* minor fix for regex strings