安装home-brew 情况下
brew install nginx
会遇到无权限问题：
==> Pouring nginx-1.8.0.el_capitan.bottle.1.tar.gz
Error: Permission denied - /usr/local/var/log/nginx
Warning: Bottle installation failed: building from source.
执行授权命令：
sudo chown -R 'your name' /usr/local
再安装
启动
sudo nginx
测试 浏览器打开下面地址
http://localhost:8080
出现welcome to nginx 就成功了
