title: postgres: ERROR: permission denied to create database even though user has permission
body: <pre><code>                            List of roles
  Role name    |     Attributes     |    Member of     |     Description
  -------------+--------------------+------------------+----------------
  my_role | Superuser, Create role, Create DB, Replication | {} | 
  my_user |                                                | {my_role} | 
  </code></pre>
  
  <p>So, now I login as my_user successfully using psql. I try to create 
  a database and it fails with error:</p>
  
  <pre><code>ERROR:  permission denied to create database
  </code></pre>
  
  <p>Any clue? I am not new to database but surely not an expert 
  postgres db admin.</p>
  
  <p>EDIT: createdb: could not connect to database template1: FATAL:  Peer authentication failed for user. If this helps?</p>