Create admin namespace

https://trello.com/c/iqzQ3SyP/16-create-a-namespace-for-admins

![image](https://cloud.githubusercontent.com/assets/8646429/5171012/4ad033e8-73e2-11e4-9678-a9acd5991a51.png)

OK, so [this line](https://github.com/NateJBeck/donations/pull/13/files#diff-98eaeef6d7d9a9f155bc7f3b2ebbceebR32) is a security risk, since anyone can edit anyone else's charity, right?

You don't have to fix it in this PR, but I'd like to bring it up.