Signed-off-by: Jie Pu <i@jaypu.com>

[Lib Support] hot model update

Signed-off-by: JimmyYang20 <yangjin39@huawei.com>

Signed-off-by: JoeyHwong <joeyhwong@gknow.cn>

Signed-off-by: JimmyYang20 <yangjin39@huawei.com>

Signed-off-by: JoeyHwong <joeyhwong@gknow.cn>

fix env missing bug

Signed-off-by: JoeyHwong <joeyhwong@gknow.cn>

1. The algorithm of HardExampleMining should be seleted by the developer.

Signed-off-by: JoeyHwong <joeyhwong@gknow.cn>

- Add docs and code comment
- fix bugs: epoch always be 1, inference result not saved, s3 upload
  fail

Signed-off-by: JoeyHwong <joeyhwong@gknow.cn>

1.fix backend env bug;
2.fix s3 upload bug;
3.fix joint_inference bug;

Signed-off-by: JoeyHwong <joeyhwong@gknow.cn>

Signed-off-by: llhuii <liulinghui@huawei.com>

lib refector and add lifelong learning

Signed-off-by: JoeyHwong <joeyhwong@gknow.cn>

Signed-off-by: congrool <783928876@qq.com>

Signed-off-by: JoeyHwong <joeyhwong@gknow.cn>

Signed-off-by: TymonXie <tymonxie@gmail.com>