In Module 1, set up GitHub authentication and clone this repo

[mfisher87]

@tsnow03, what do you think? The instructions currently clone the CryoCloud website, but I think it makes sense to clone this repo instead. In downstream modules, we'll use Notebooks included in this repo and demo building a website from this repo. Having it already cloned will be a head start :)

What do you think of also including GitHub auth setup (using GHAUTH.ipynb)? We will be commiting and pushing in module 5, perhaps in other modules.