參考：
pip "Cannot uninstall 'six'. It is a distutils installed project..." 解決方法
在升級 six 時遇到無法安裝的問題，錯誤日志如下：
Cannot uninstall 'six'. It is a distutils installed project and thus we cannot accurately determine which files belong to it which would lead to only a partial uninstall.導致錯誤的原因：Six issue when installing package
解決方法：
sudo pip install six --upgrade --ignore-installed six