创建分支后，git pull拉下代码出现：
There is no tracking information for the current branch.
Please specify which branch you want to merge with.
See git-pull(1) for detailsgit pull <remote> <branch>
If you wish to set tracking information for this branch you can do so with
git branch --set-upstream-to=origin/<branch> master
解决方法：
git pull origin 3.0.2
