$ git reset –hard HEAD^ 回退到上个版本
$ git reset –hard HEAD~3 回退到前3次提交之前，以此类推，回退到n次提交之前
$ git reset –hard commit_id 退到/进到 指定commit的sha码
强推到远程：
$ git push origin HEAD –force
删除本地分支
git branch -d branch_name
删除远程分支
git branch -r -d origin/branch_name
git push origin :branch_name
git修改本地和远程分支名称
git branch -m old_branch new_branch # Rename branch locally
git push origin :old_branch # Delete the old branch
git push –set-upstream origin new_branch # P