问题1
问题描述：
Can't Update
No tracked branch configured for branch master or the branch doesn't exist.
To make your branch track a remote branch call, for example,
git branch --set-upstream-to=origin/master master
解决方案：
git branch --set-upstream-to=origin/master
问题2
问题描述：
Can't Update
fatal: refusing to merge unrelated histories
解决方案：
方案1：允许不相关历史提交，并强制合并
git pull origin master --allow-unrelated-histories
方案2：强制提交
git push --force origin master
