build admin section

[willkg]

We should build a very small admin section that allows certain people to create projects, create sprints in those projects, edit projects, edit sprints, etc.

The list of admin can be maintained in settings. Or it can be its own table. We don't have user accounts in Ernest so far, so we can fudge this part for now.

• [x] implement project admins
• [x] create new sprint
• [x] edit sprint
• [ ] delete sprint
• [ ] implement site admin
• [ ] create project

[willkg]

Pull #29 adds project admins to the soup. It also adds a "new sprint" form. That covers part of this.

[willkg]

I'm working on some of this now.