Test app for Rails issue #2142

to setup, run:

bundle install rake db:create:all rake db:migrate bundle exec rails s

then go to http://localhost:3000

and you should see "hello world". Now go in and change config/database.yml; perhaps change the username to root2

now it will fail. However if you look in app/controllers/public_controller.rb, we would expect the exception to be rescued; but it is not. This is because the QueryCache is creating a connection and if it fails that low down it misses almost everything (possibly including hoptoad?)