增加teacher页面
新增src/snippets文件夹，用于存储临时代码段
Merge branch 'master' of https://github.com/happiefire/tgj
Merge branch 'master' of https://github.com/cuimichael/tgj
shuo:修改class-new
Merge branch 'master' of https://github.com/happiefire/tgj
cui:update class-new.jade