Remove all history from git.

file.sh

git checkout --orphan newBranch
git add -A  # Add all files and commit them
git commit
git branch -D master  # Deletes the master branch
git branch -m master  # Rename the current branch to master
git push -f origin master  # Force push master branch to github

Reminder for.
http://stackoverflow.com/questions/9683279/make-the-current-commit-the-only-initial-commit-in-a-git-repository