title: close session inside a rails engine
body: <p>I have an engine called coupons inside my rails application, I want to close session but it gives me an error that says the URL does not exist, but outside the engine it is possible to close session:</p>
  
  <pre><code>&lt;a href="&lt;%= main_app.destroy_user_session_path %&gt;"
      method: "delete"
      class="btn-login-type"&gt;log out
  &lt;/a&gt;
  </code></pre>
  
  <p><strong>The error I get:</strong></p>
  
  <pre><code>No route matches [GET] "/users/sign_out"
  </code></pre>
  
  <p>(as I said, this works outside the engine, but not inside)</p>