* replace tensorboard with summary to support VDL in the future

* unittest

* rename keys for record

* yapf

* update comments for ES

* check dependence on paddle or torch

* update readme

* update readme#2

* users can still use parl.remote when no DL framework was found

* yapf

* fix paddle version bug

* add gym dependence (introduced by MADDPG)

* recall

* add learning curve for ES

* add learning curve for ES

* support new APIs of the cluster

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* rename learner.py

* Update README.md

* Update README.md

* Update README.cn.md

* Update README.md

* Update README.cn.md

* Update README.md

* ES example

* refine settings

* fix yapf

* refine documentation; remove csv logger

* fix bug

* merge learner.py and train.py; add version requirements of gym and atari_py

* unify actor num