* add traceback of remote function calling

* assert traceback information

* 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

* .

* Update remote_decorator.py

* Update README.md

* add an figure for the demonstration about parallelization

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* add a link to IMPALA

* 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