Feat: Add Auth + Schools CRUD

[sean-dickinson]

What

• Adds the user model and rails authentication scaffold
• Adds the schools CRUD

Context

• Initially I was going to add the auth and the schools separately but to really have a test for the admin I wanted to add a root route so we could prove it works. Initially I had a dummy route but that felt weird, so I'm including both here.
• This is extremely vanilla. I did slightly modify the schools views but did 0 styling. I don't want to get into styling at all here, I'll pull in some css framework to make it not ugly at the end.