title: WordPress wp_insert_post not inserting tags
body: <p>I am trying to insert a post with this code:</p>
  
  <pre><code>$my_post = array(
                  'post_type'    =&gt; "essays",
                  'post_title'    =&gt; 'TEST 3',
                  //'post_content'  =&gt; $content,
                  'post_status'   =&gt; 'draft',
                  'post_author'   =&gt; 1,
                  //'post_category' =&gt; $cat,
                  'tags_input'    =&gt; 'TQM,tag',
          );
  
  $post_id = wp_insert_post($my_post);
  </code></pre>
  
  <p>Everythings works ok except the tags, it does not insert any of them.
  Any idea?</p>