Added homework directory and demo.md
yujie first file
张世萌添加
new add
add
Merge pull request #2 from BlackPearl2014/master

余杰，你好
Update license-yujie.md

请更新这个文件
Merge pull request #1 from yujie13312963854/master

获取原作者修改
完成
Merge pull request #3 from BlackPearl2014/master

已经合并了提交，余杰
Update license-yujie.md

modify by amliang
Merge pull request #5 from amliang/master

license-yujie.md   已经merge了，请爱民查收
cource experience
Merge pull request #6 from xupeipei/master

cource experience  yujie
Merge pull request #2 from yujie13312963854/master

填写课程感受
完成课程感受
Merge pull request #7 from BlackPearl2014/master

张世萌课程感受   已经merge
Rename license-yujie.md to license-team6.md
Merge pull request #3 from yujie13312963854/master

well done