Fix The Octopress Github Repo Sidebar Item

I noticed yesterday that all of the sudden, that little thing on the side that lists my github repos quit working. I updated my octopress sources to match the current master, but that failed to fix the problem. Googling around a little, I saw that Github end-of-lifed v1 and v2 of their API yesterday, which promptly broke the Github repo thing in Octopress. Fortunately you can get the same general information from the new API, but it requires some code changes.