title: WC_Subscription::update_dates( $dates, $timezone ) is no longer valid?
body: <p>Seems as though the function 
  <strong>WC_Subscription::update_dates( $dates, $timezone )</strong> is no longer valid in the 3.0+ update, because the of the CRUD platform?</p>
  
  <p>How do I go about finding the right function to use, as this is what's on the website. I basically have a loop that gets all active subscriptions and I want to update the <strong>next_payment_date</strong>. Now, if you do this just through the database, it won't update, so you have to run it through this function so it updates all the schedulers etc. </p>
  
  <p>If I run, something similar to this, I get a 500 error. Any help would be greatly appreciated. </p>
  
  <pre><code>&lt;?php 
  WC_Subscription::update_dates( array(
        'next_payment' =&gt; '2017-05-30 04:30:00'
  ) );
  ?&gt;
  </code></pre>