User stories for review.

@hughhn @rcarino @josemontesdeoca @jaredzimmerman 

Proposed user stories for KIPP.  Please review.  Also, additional clarifying questions here:
https://docs.google.com/document/d/1hFFxBRcWRuEXc62et_yvSRwbhLXH4CCz7YCU4DHXhvI/edit

I'm thinking we don't need to go too crazy on security here. This isn't a banking app, so  a hijacked teacher account can't ruin anyone's life.

I'm also thinking a standard "stay logged in" after authenticating would be sufficient for demo day.