Heroku Rails app not loading pages

Heroku Rails app not loading pages

I'm publishing a Rails app on Heroku for the first time, and am running
into an error. Everything works great, except only the landing page loads.
From the landing page, there are sign-up and log-in buttons for Devise,
but they just throw 500 error pages. I opened up the Heroku logs and see
these:
2013-08-27T19:00:55.036186+00:00 app[web.1]: Processing by
Devise::SessionsController#new as HTML
2013-08-27T19:00:55.035363+00:00 heroku[router]: at=info method=GET
path=/users/sign_in host=infinite-escarpment-6269.herokuapp.com
fwd="98.245.21.165" dyno=web.1 connect=3ms service=20ms status=500
bytes=643
2013-08-27T19:00:55.773025+00:00 heroku[router]: at=info method=GET
path=/favicon.ico host=infinite-escarpment-6269.herokuapp.com
fwd="98.245.21.165" dyno=web.1 connect=2ms service=14ms status=304 bytes=0
2013-08-27T19:00:01.630144+00:00 heroku[router]: at=info method=GET
path=/users/sign_up host=infinite-escarpment-6269.herokuapp.com
fwd="98.245.21.165" dyno=web.1 connect=5ms service=150ms status=500
bytes=643
I don't see any error codes in here. My app is using PostgreSQL and the
only commands I ran on the database were heroku run rake db:create:all and
heroku run rake db:migrate. Do I need to make any changes in my
database.yml file to get the site working on Heroku? Do I need to write
any migrations to get the site working on Heroku? I'm new to all of this,
so I'm not sure. I've just been following the getting started instructions
on Heroku.
UPDATE I tailed the logs and see this error message relating to PostgreSQL:
ActiveRecord::StatementInvalid (PG::Error: ERROR: relation "users" does
not exist
This error message is familar to me, but I can't remember what to do about
it.