Merge branch 'model-cleanup' into 'master'

bob/ip/binseg/configs/models/driu.py

bob/ip/binseg/configs/models/driu_bn.py

bob/ip/binseg/configs/models/driu_bn_ssl.py

bob/ip/binseg/configs/models/driu_od.py

bob/ip/binseg/configs/models/driu_ssl.py

bob/ip/binseg/configs/models/hed.py

bob/ip/binseg/configs/models/m2unet.py

bob/ip/binseg/configs/models/m2unet_ssl.py

bob/ip/binseg/configs/models/resunet.py

bob/ip/binseg/configs/models/unet.py

bob/ip/binseg/engine/ssltrainer.py

bob/ip/binseg/engine/trainer.py

bob/ip/binseg/modeling/backbones/mobilenetv2.py

bob/ip/binseg/modeling/backbones/resnet.py

bob/ip/binseg/modeling/backbones/vgg.py

bob/ip/binseg/models/__init__.py

bob/ip/binseg/models/backbones/__init__.py

bob/ip/binseg/models/backbones/mobilenetv2.py

bob/ip/binseg/models/backbones/resnet.py

bob/ip/binseg/models/backbones/vgg.py