Add private iPad repo to phabricator

Test Plan:
I ran it. Only trick was that toby didn't trust github's host keys so I did a manual clone to /tmp and told ssh it was okay.

```
Adding new repository iPad: url=git@github.com:Khan/iPad, callsign=GI, vcs=git, destdir=/home/ubuntu/phabricator/repositories/git/iPad
```

Now we have http://phabricator.khanacademy.org/diffusion/GI/.

Reviewers: csilvers

Reviewed By: csilvers

CC: laura

Differential Revision: http://phabricator.khanacademy.org/D5202