* add SGD and Adam Optimizer for DeepES

* update deepes readme

* add warning when input different size in the same param update()

* add error return in update(), add optimizer.cc

* separate SGD and Adam, optimizer type in config is not case sensitive

* delete optimizer.cc

* config optimizer in deepes.proto

* more readable

* update maddpg readme, fixed gym version

* fix paddle version bug

* add gym dependence (introduced by MADDPG)

* recall

* 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