For those who are using Github services, and pushing their code via terminal, you may encounter this problem where you will see a folder named .svn on each folder of your code.
So if you want to delete this folder, follow this step below:
First, pull your code from Github to your computer:
git pull origin master
Then, use this command to find folder .svn and delete it:
find . -name '.svn' | xargs git rm -rf --ignore-unmatch
Last, push your code back to Github server:
git push origin master