WIP Assistant / TaskPlans / Sprint 3

Don't merge, WIP.

To test it out, switch to this branch and then run:

```
rake db:drop
rake db:migrate
rake sprint:003
rails server
```

Go to `http://localhost:3001`, sign in as the sole user (printed out in the sprint:003 run above.


Oh I just noticed that `peers` is protected, so we can't call it externally. I was going to say you could get rid of `peers` and add it inline in the method above, but if it's protected we don't need to do that. So this is fine I guess.