* add IMPALA algorithm and some common utils

* update README.md

* refactor files structure of impala algorithm; seperate numpy utils from utils

* add hyper parameter scheduler module; add entropy and lr scheduler in impala

* clip reward in atari wrapper instead of learner side; fix codestyle

* add benchmark result of impala; refine code of impala example; add obs_format in atari_wrappers

* Update README.md

* refine remote module, add heartbeat machanism and unittest

* yapf

* yapf

* support get ip address in CentOS, add dependence

* yapf

* add dependence in Dockerfile

* refine message_tag, Compatible with Python2 and python3

* refine unittest and comments

* remove ParlError, use to_pybytes api to compatible with Python 2 and python 3

* Not need to use to_pybytes

* use parl-test docker image for unittest, which has python2 and python3 env

* test different release order of sockets

* test for different closing way fo context and socket

* tmp commit for debug in teamcity

* tmp commit for debug in teamcity

* tmp commit for debug in teamcity

* use zmq.context destroy to close multi-thread socket, refine RemoteError

* set linger=0 for command socket in RemoteObject

* remove close context unittest

* fix codestyle

* fix codestyle

* rename parl.remote to parl.remote_class; will not exit client when having errors in function call; use sepereate server port in unittest to avoiding closing server manually

* rename parl.remote to parl.remote_class; will not exit client when having errors in function call; use sepereate server port in unittest to avoiding closing server manually

* fix typo

* remove unnecessary try/except in reply loop of client

* import RemoteManager to parl; refine comment

* add PPO example

* Update Readme

* Update Readme

* fix codestyle

* Update Readme

* refine action mapping

* add more unitest case

* remove unnecessary params initialize, add more comments, add benchmark result

* rename

* remove PARL dependence in readme of examples

* redesign basic class in PARL

* code style fixed

* update yaml's version

* update yaml's version & update code to fix style problem

* add debug message for  function

* delete test code

* rename function: has_fun -> has_func

* fix wrapper of dynamic_lstm cannot support h_0 and c_0 initialization, fix bug of wrapper of dynamic_gru

* use sampling_id of fluid to sampling ids

* remove test simple games unittest, avoid timeout

* change pip source