使用此方法可用于由MySQL官网下载安装的任一版本MySQL，具体操作如下：
sudo rm /usr/local/mysql
sudo rm -rf /usr/local/mysql*
sudo rm -rf /Library/StartupItems/MySQLCOM
sudo rm -rf /Library/PreferencePanes/My*
rm -rf ~/Library/PreferencePanes/My*
sudo rm -rf /Library/Receipts/mysql*
sudo rm -rf /Library/Receipts/MySQL*
sudo rm -rf /private/var/db/receipts/*mysql*
亲测可行环境：
Mac系统版本：Mac OS 10.14.3
MySQL版本：MySQL 8.0.15
若需重装MySQL，建议重启系统
