Gitlab通过Webhook实现Push代码后Jenkins自动构建

https://www.centos.bz/2018/05/gitlab%e9%80%9a%e8%bf%87webhook%e5%ae%9e%e7%8e%b0push%e4%bb%a3%e7%a0%81%e5%90%8ejenkins%e8%87%aa%e5%8a%a8%e6%9e%84%e5%bb%ba/#5.%20%E7%94%9F%E6%88%90%E5%9B%9E%E8%B0%83%E5%9C%B0%E5%9D%80%E5%92%8CSecret%20Token