title: rake aborted! ERROR: must be owner of database
body: <p>I am working through Michael Hartl's excellent <a href="http://ruby.railstutorial.org/chapters/modeling-and-viewing-users-one#sec%3auser_validations">tutorial</a> but when trying to prepare the test database with the command: 
  bundle exec rake db:test:prepare
  I get this error message: </p>
  
  <p>ERROR:  must be owner of database sample_app_test...</p>
  
  <p>which I never got when using the development database, because I had created the following database role for my Rails app:</p>
  
  <p>CREATE ROLE demo_app WITH CREATEDB LOGIN</p>
  
  <p>(this is using Postgresql)</p>
  
  <p>Does anyone understand why this is failing in the test environment? 
  TIA...</p>