* test=develop, update install doc

* add setuptools dependency

* Update compile_Ubuntu.md

update cudnn version

* Update install_Ubuntu.md

update cudnn version

* Update install_CentOS.md

update cudnn version

* test=develop, refine ubuntu cuda support

* test=develop, refine ubuntu cuda support

* test=develop, refine python support on python3.5

* fix python2 in ubuntu16.04 need gcc 5.4

* add nccl related doc

* refine doc

* add gpu fast install doc

* refine command of pip

* add avx off for mac complie

* refine code

* refine doc

* fix python only support 64bit

* fix doc problem

* refine doc

* remove centos7 support cuda8 compile

* fix centos6 compile not support