* update lr interface and support  training on single gpu

* yapf

* update warning message

* update warning message

- add prioritized dqn
- fix#239

* fix self.alg

* torch agent initialization

* remove definition of self.alg in PPO

* replace self.algorithm with self.alg

* remove unnecessary definition of self.alg

* fix cn readme

* unittest

* yapf

* upgrade DQN's lr interface compatibility

* yapf

* update example DQN

* ping the master before connection

* yapf

* fix comments

* remove the useless library

* install ping for the docker environment

* remove protobuf intallation

* remove evokit test

* replace tensorboard with summary to support VDL in the future

* unittest

* rename keys for record

* yapf

* state to obs

* yapf & update softlink in offline-q-learning

* remove version 1.3 warnings

* update

* yapf

* add algorithms test

* Update algs_test.py

* Update algs_test.py

add SAC DDPG TD3 tests

* yapf

* fix a2c cannot run in paddle 1.6.0

* fix impala compatibility

* yapf

* fix compatibility issue with the newest paddle

* remove logging lines

* resolve the compatibility issue with the newest paddle

* yapf
Co-authored-by: Nrobot <zenghongsheng@baidu.com>

* fix compatibility issue with the newest paddle

* remove logging lines
Co-authored-by: Nrobot <zenghongsheng@baidu.com>

* add maddpg example

* format with yapf

* fix coding style

* fix coding style

* unittest without import multiagent env

* update maddpg code

* update maddpg readme

* add copyright comments

* update parl.maddpg without import gym

* update NeurlIPS2018.gif to NeurlIPS2019.gif

* update readme and comments

* add maddpg example

* format with yapf

* fix coding style

* fix coding style

* unittest without import multiagent env

* update maddpg code

* update maddpg readme

* add copyright comments

* add sac

* Training pipeline of NeurIPS2019-Learn-to-Move-Challenge

* fix grammar mistakes

* release 1.2.1

* copyright

* fix bug

* refine README

* refine README

* fix typo

* Update README.md

* Update README.md

* add TD3

* update

* yapf.....

* Update train.py

* add Double & Dueling DQN

* yapf......................

* update

* Update train.py

* fix bug of ParamAttr

* refine imports of unittest

* remove previous algorithms; use the forward function in parl.Model

* remove abundant lines

* yapf

* intra-version: move parl.framework into parl.core.fluid

* add folder: parl.core

* remove former test folders

* yapf

* yapf0.24