Qiita env issue 359

Have to run to a meeting, but I will be continuing this afterwards.  Thought I'd put this in so that people could see the direction I'm heading.  Having the admin_user/password in the config will facilitate our use of the live system (qiita.colorado.edu), and I think it makes sense to have this anyways (although it would be nice not to have to have passwords, esp the admin password, in the config file; see `TODO` comments in code)