Revert "Merge pull request #14 from newfold-labs/hotfix/fix-deprecate…

…d-warning"

This reverts commit 4c9854f, reversing
changes made to a5a683c.

includes/Models/PriorityQueue.php

@@ -13,7 +13,7 @@ class PriorityQueue extends \SplPriorityQueue {
 	 * @param mixed $priority2 Second Priority Queue
 	 * @return int
 	 */
-	public function compare( $priority1, $priority2 ) : int {
+	public function compare( $priority1, $priority2 ) {
 		if ( $priority1 === $priority2 ) {
 			return 0;
 		}