Merge pull request #1 from strivel/master

增加readme信息
修改readme信息
修改readme信息
fetch命令

远程仓库的代码更新到本地
补充fetch命令
更新pull、fetch命令
update
update dev to branch
Merge branch 'master' into dev

Conflicts:
	README.md
Merge branch 'dev'
测试合并dev分支新代码到master
Merge remote-tracking branch 'origin/dev'

Conflicts:
	README.md
新建分支尝试
利用Github管理Git
更新fetch命令