* add VisualDL as summary logging backend

* yapf

* copyright

* using visualdl as the default logging tool

* only support linux at the moment

* yapf

* yapf

* remove dependency on six

* unittest

* yapf

* replace tensorboard with summary to support VDL in the future

* unittest

* rename keys for record

* yapf

* fix a number of bug

* update comments

* paddle license

* revert the change on client_not_init_test.py

* fix timeout bug & unnitest

* add unit test for potential bugs

* yapf

* unit test

* logger

* logger#2

* fix job's bug that will cause dead-lock

* fix bug

* add missing files

* solve hanging

* fix comments; exit job completely

* hanging problem

* hanging problem#2

* hanging_program#3

* CMAKE

* remove unused variables

* fix some problems of tensorboard

* yapf

* add tensorboardX

* yapf

* Code License

Now we can check the parl version by calling parl.__version__

* fix typo

* Update README.md

* Update README.md

* Update README.md

* soft depend on fluid; add module to monitor client status

* improve performance of IMPALA example

* fix bug of some client cannot exit normally

* refine comment

* .

* 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 setup.py for installation

* rename agent.py to make it consistent with other framework base

* namespace bug