Permission denied: '/usr/local/lib/python2.7/dist-packages/pip-9.0.1-py2.7.egg/EGG-INFO/requires.txt
主要参考：https://stackoverflow.com/questions/21093002/error-could-not-create-usr-local-lib-python2-7-dist-packages-virtualenv-suppo之前必须是sudo pip -V才能查看Pip的版本You don't have permission to the Pyth
