github/teach.github.com — pull request #175 by jordanmccullough (2013-07-16 15:22:54+00:00)
Title: Fix commit tree diagram typos/errors

Tree node in diagram referenced to blob elements when label should be tree ref.

![screen shot 2013-07-16 at 9 22 02 am](https://f.cloud.github.com/assets/352082/805692/82881230-ee2b-11e2-9269-cd9e65149b70.png)

//cc @tlberglund