An implemention of offline RL on recommender system

@author: misajie @update: 20220123

File organization:

• RecEnv
• ClassicalRL
• OfflineRL

In progress:

• Classical off-policy models construction and application on existing environments (Recsim, Virtual Taobao)
• Reconstruct simulator-free model, eg. feedrec
• Modify Recsim to fit Wechat short video dataset and run off-policy models and evaluate the result
• Generate reply samples from short video recommendation environment
• Build classical offline models
• Build original offline model
• Evaluate new model
• add autoML