* update solver.py and model_builder.py

* update solver.py

* update infer.py

* update model_builder.py for fitting different aug_method

* update model_builder.py

* update model_builder.py

* update export process

* save best model

* update train.py

* update train.py

* update train.py

* eval for last epoch model

* check model path

* check TEST.TEST_MODEL

* reconsitution humanseg

* first refactor humanseg

* update humanseg.py and add main.py

* release change log

* update readme

* update readme

* upload fast-scnn image

* update readme

* update readme

* replace fluid.layers.data

* update api fluid.data and fluid.io.DataLoader
Co-authored-by: NLielinJiang <jianglielin@baidu.com>
Co-authored-by: NLielinJiang <50691816+LielinJiang@users.noreply.github.com>