If you are prompted for login and password every time you try git push your commit this means that you have cloned your repository using HTTPS protocol instead of SSH.
If you have your SSH set up as per github help page and all is working as per https://help.github.com/articles/generating-ssh-keys/
you need to enter the following command to change your cloned repository on your PC from https to SSH
git remote set-url origin firstname.lastname@example.org:username/repo.git
once this is done you can type
and this should send a commit to your git hub account without asking for login and password.