Anybody seen this error and know what to do?
I\'m using the terminal, I\'m in the root, the GitHub repository exists and I don\'t know what to do now.
GitHub isn't able to authenticate you. So, either you aren't setup with an SSH key, because you haven't set one up on your machine, or your key isn't associated with your GitHub account.
You can also use the HTTPS URL instead of the SSH/git URL to avoid having to deal with SSH keys. This is GitHub's recommended method.
Further, GitHub has a help page specifically for that error message, and explains in more detail everything you could check.