Add local storage adapter

This is how we'll store the user's auth token.
Add sessions controller + routes

Also add the API key model that we'll use to persist our auth token
Require auth for everything but sessions + dashboard controllers

I unabashedly stole these specs from Steven Harman.
Implement logging out
Persist auth via cookies
Redirect unauthenticated users to login as appropriate
Make the login page a little prettier
Remove some console.logs, clean up invalid password message