These days when I create a new repository on GitHub on the setup page I get:
git remote add origin https://github.com/nikhilbhardwaj/abc.git
git push -u orig
GitHub
git config --global url.ssh://git@github.com/.insteadOf https://github.com/
BitBucket
git config --global url.ssh://git@bitbucket.org/.insteadOf https://bitbucket.org/
That tells git to always use SSH instead of HTTPS when connecting to GitHub/BitBucket, so you'll authenticate by certificate by default, instead of being prompted for a password.