路由设计
| 请求方法 | 请求路径 | get 参数 | post 参数 | 备注 |
| GET | /students | | | 渲染首页 |
| GET | /students/new | | | 渲染添加 |
| POST | /students | | name age gender hobbies | 渲染添加 |
| GET | /students/edit | id | name age gender hobbies | 渲染编辑 |
| POST | /students/edit | id | | 渲染编辑 |
| GET | /students/delete | id | | 渲染删除 |
