Fix issue where unit test does not attach comments to a post

Author: dshanske

tests/test-rendering.php

@@ -12,12 +12,14 @@ public function setUp() {
 
 	public function make_comments( $num, $semantic_linkbacks_type = 'like' ) {
 		$comments = array();
+		$post_id = wp_insert_post(['post_title'=>'Some Post']);
 		for ( $i = 0; $i < $num; $i++ ) {
 			$id = wp_new_comment(
 				array(
 					'comment_author_url' => 'http://example.com/person' . $i,
 					'comment_author'     => 'Person ' . $i,
 					'comment_type'       => 'webmention',
+					'comment_post_ID'    => $post_id
 				)
 			);
 			add_comment_meta( $id, 'semantic_linkbacks_type', $semantic_linkbacks_type );