**Highlights**
- Support MobileNetV3, DMNet, APCNet. Add models of ResNet18V1b, ResNet18V1c, ResNet50V1b, ResNet101V1b.
**Bug Fixes**
- Fixed CPU TTA ([276](https://github.com/open-mmlab/mmsegmentation/pull/276))
- Fixed CI for pip 20.3 ([307](https://github.com/open-mmlab/mmsegmentation/pull/307))
**New Features**
- Add ResNet18V1b, ResNet18V1c, ResNet50V1b models ([316](https://github.com/open-mmlab/mmsegmentation/pull/316))
- Support MobileNetV3 ([268](https://github.com/open-mmlab/mmsegmentation/pull/268))
- Add 4 retinal vessel segmentation benchmark ([315](https://github.com/open-mmlab/mmsegmentation/pull/315))
- Support DMNet ([313](https://github.com/open-mmlab/mmsegmentation/pull/313))
- Support APCNet ([299](https://github.com/open-mmlab/mmsegmentation/pull/299))
**Improvements**
- Refactor Documentation page ([311](https://github.com/open-mmlab/mmsegmentation/pull/311))
- Support resize data augmentation according to original image size ([291](https://github.com/open-mmlab/mmsegmentation/pull/291))