title: Setting MongoDB authorization configuration in Python-Eve
body: <p>I am using Python-Eve with a MongoDB instance with authorization enabled, so I need to provide user/pass credentials in <code>settings.py</code> to properly initialize Python-Eve API.</p>
  
  <p>If used the <code>MONGO_URI</code> global configuration setting, to declare the database endpoint as described <a href="http://python-eve.org/config.html?highlight=mongo_uri" rel="nofollow">here</a> it works just right:</p>
  
  <pre><code>MONGO_URI = 'mongodb://&lt;someuser&gt;:&lt;somepass&gt;@&lt;host&gt;/&lt;auth_db&gt;'
  </code></pre>
  
  <p>But if I try to use the other possible way according to Eve documentation, which is to declare at settings.py, individual settings for each part or the URI, like this:</p>
  
  <pre><code>MONGO_HOST = &lt;host&gt;
  MONGO_PORT = 27017
  MONGO_DBNAME = &lt;mongo_db&gt;
  MONGO_USERNAME = &lt;someuser&gt;
  MONGO_PASSWORD = &lt;somepass&gt;
  MONGO_AUTHDBNAME = &lt;auth_db&gt;
  </code></pre>
  
  <p>I get an error like the one below:</p>
  
  <pre><code>pymongo.errors.OperationFailure: command SON([('saslStart', 1), ('mechanism', 'SCRAM-SHA-1'), ('autoAuthorize', 1), ('payload', Binary(b'n,,n=root,r=MzcxMTQ1MTM3MTExNDYwNg==', 0))]) on namespace testapp.$cmd failed: Authentication failed.
  </code></pre>
  
  <p>What is missing to make it work this way?</p>