安装mysql5.7遇到的坑，mac刚上手，不是很熟，配置个mysql都用了一晚上。
参考 https://segmentfault.com/a/1190000004061246
1.配置环境变量
export PATH=$PATH:$GOROOT/bin:$GOPATH/bin:/usr/local/mysql/bin
2.登录
mysql -u root -p ：按回车
输入密码（安装MySQL时有提示临时密码，通知上也有）...
确定后 提示
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 105
Server version: 5.7.17
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
然后设置密码：
set password='密码';
ok！
