title: Role does not exist and unable to create database when using PostgreSQL
body: <p>I am using Heroku for my application and it requires PostgreSQL but you can still use SQLite3 for development. Since Heroku strongly advised against having 2 different databases I decided to change to PostgreSQL for development. I installed the <code>gem pg</code> and also went to the official PostgreSQL site to get the Windows installer and also changed my <code>database.yml</code>. During installation it requires a password for PostgreSQL so I made one. 
  I had to change the <code>pg_hba.conf</code> file from using <code>md5</code> to <code>trust</code> in order get past: <code>fe_sendauth: no password supplied</code> when trying to create the database.</p>
  
  <pre><code># TYPE  DATABASE        USER            ADDRESS                 METHOD
  
  # IPv4 local connections:
  host    all             all             127.0.0.1/32            trust # was md5
  # IPv6 local connections:
  host    all             all             ::1/128                 trust # was md5
  # Allow replication connections from localhost, by a user with the
  # replication privilege.
  #host    replication     postgres        127.0.0.1/32            trust
  #host    replication     postgres        ::1/128                 trust
  </code></pre>
  
  <p>After getting rid of that though, I now get this:</p>
  
  <pre><code>$ rake db:create
  (in C:/app)
  FATAL:  role "User" does not exist 
  Couldn't create database for {"adapter"=&gt;"postgresql", "encoding"=&gt;"utf8", 
  "database"=&gt;"app_test", "pool"=&gt;5, "username"=&gt;nil, "password"=&gt;nil} 
  </code></pre>
  
  <p>I do still have my <code>development.sqlite3</code> and <code>text.sqlite3</code> present, could that be the issue? What must be done?</p>
  
  <p>Here is my full gist: <a href="https://gist.github.com/1522188" rel="noreferrer">https://gist.github.com/1522188</a></p>