For SPIS, you’ll need an account at github.com. You’ll also need to belong to the ucsd-cse-spis-2016 organization on github.
An instructor or mentor will invite you to the organization. To accept the invitation
Navigate to the page https://github.com/ucsd-cse-spis-2016
Look for something like the following near the top of the page. Click to view the invitation.
Then, click to accept the invitation
You should see a confirmation like this one.