title: Getting minimum order amount for 'Free Shipping' method in checkout page
body: <p>I have did tried to use the code from this answer: <br>
  <a href="https://stackoverflow.com/questions/26582039/how-to-get-minimum-order-amount-for-free-shipping-in-woocommerce">How to get minimum order amount for free shipping in woocommerce</a></p>
  
  <p>But it return a <strong><code>NULL</code></strong> result and I can't find the way to fix this code until now. </p>
  
  <p>How can I get the right <strong>minimun order amount</strong> on checkout page?</p>
  
  <p>Thanks</p>