Initial data commit

Task/Queue-Usage/PHP/queue-usage.php

@@ -0,0 +1,10 @@
+<?php
+$queue = new SplQueue;
+echo $queue->isEmpty() ? 'true' : 'false', "\n";  // empty test - returns true
+// $queue->dequeue();                             // would raise RuntimeException
+$queue->enqueue(1);
+$queue->enqueue(2);
+$queue->enqueue(3);
+echo $queue->dequeue(), "\n";                     // returns 1
+echo $queue->isEmpty() ? 'true' : 'false', "\n";  // returns false
+?>