title: custom discount applied twice in magento 2
body: <p>I have applied custom discount in magento 2.1 using <a href="http://www.magestore.com/magento-2-tutorial/how-to-add-magento-2-custom-discount/" rel="nofollow noreferrer">this</a>. Everything is working on local system but when I deploy the changes on server, discount get subtracted twice from the total.
  Can any one any idea about this? </p>
  
  <p>Sales.xml </p>
  
  <pre><code>&lt;?xml version="1.0"?&gt;&lt;config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Sales:etc/sales.xsd"&gt;
  &lt;section name="quote"&gt;
      &lt;group name="totals"&gt;
          &lt;item name="test_discount" instance="Namespace\Modulename\Model\Quote\Discount" sort_order="500"/&gt;
      &lt;/group&gt;
  &lt;/section&gt;
  </code></pre>
  
  <p></p>