说明：例如将代码提交到git仓库，将一些敏感信息提交，所以需要删除提交记录以彻底清除提交信息，以得到一个干净的仓库且代码不变

1.Checkout
git checkout –orphan latest_branch

  1. Add all the files
    git add -A

  2. Commit the changes
    git commit -am “commit message"

  3. Delete the branch
    git branch -D master

5.Rename the current branch to master
git branch -m master

6.Finally, force update your repository
git push -f origin master