测试命令就是这么一条：
ab -t 10 -c 10 <http://www.darwin.com/>
在不做任何优化的情况下，结果是：
Requests per second: 17.54 [#/sec] (mean)
Requests per second: 19.96 [#/sec] (mean)
Requests per second: 14.12 [#/sec] (mean)
.env 里面设置 APP_DEBUG=false
Requests per second: 21.59 [#/sec] (mean)
Requests per second: 22.02 [#/sec] (mean)
Requests per second: 19.20 [#/sec] (mean)
将 PHP 版本从 5.6 升级到 7.1，直接安装最新版本的 XAMPP：
Requests per second: 30.46 [#/sec] (mean)
Requests per second: 26.36 [#/sec] (mean)
Requests per second: 26.11 [#/sec] (mean)
启用 Opcache：
Requests per second: 207.45 [#/sec] (mean)
Requests per second: 202.04 [#/sec] (mean)
Requests per second: 177.29 [#/sec] (mean)
把 Apache 换成 Nginx：
目前php7.1.4配置以后无法使用到opcache，等以后版本稳定以后再更新这个数据
