title: SQLAlchemy no password supplied error
body: <p>This is probably a silly error but I cannot seem to find a satisfying solution.</p>
  
  <p>When running <code>db.create_all()</code>, I got the following error.</p>
  
  <pre><code>sqlalchemy.exc.OperationalError: (OperationalError) fe_sendauth: no password supplied  None None
  </code></pre>
  
  <p>My database link is set as </p>
  
  <pre><code>'postgresql://localhost/db_name'
  </code></pre>
  
  <p>This worked fine on my Mac and Heroku, but is not OK on ubuntu (digitalocean). </p>
  
  <p>Any ideas what I might be doing wrong?</p>