Build docs

I am on the fence about whether I should submit this against 2.4-testing or master. I feel like it's fine to go into master, but if the reviewer disagrees I could be talked into putting it in 2.4 or 2.5.
I replaced these three lines with this:

```
$ for r in {,_puppet,_rpm}; do git clone git@github.com:pulp/pulp$r.git; done;
```