step1:
https://help.github.com/articles/configuring-a-remote-for-a-fork/
step2:
https://help.github.com/articles/syncing-a-fork/
fork and PR
https://gist.github.com/Chaser324/ce0505fbed06b947d962
pull and apply a patch
https://stackoverflow.com/questions/7827002/how-to-apply-a-git-patch-when-given-a-pull-number
update centos python:
https://blog.fazero.me/2016/10/13/centos-update-python/
cd /home/
virtualenv --python=/usr/local/python2.7.12/bin/python2.7 py2.7.12ENV
source py2.7.12ENV/bin/activate