title: How to set up relations between features and steps in lettuce?
body: <p>I'm using lettuce BDD framework for python. 
  In examples all scenarios use methods from only one *.py file - steps.py
  How to set up relations between *.feature and its *.py file?</p>
  
  <p>I need these feature files: </p>
  
  <pre><code>auth.feature
  pay.feature
  </code></pre>
  
  <p>and these py files</p>
  
  <pre><code>auth.py
  pay.py
  </code></pre>
  
  <p>I need this: scenarios from the <code>auth.feature</code> refer to the methods only in <code>auth.py</code>
  and scenarios from the pay.feature refer only to the methods in <code>pay.py</code> </p>