Merge pull request #21 from fh-jashmore/check-response-message

Check for Messages in response

Author: dusterio

src/Sqs/Queue.php

@@ -62,7 +62,7 @@ public function pop($queue = null)
             'AttributeNames' => ['ApproximateReceiveCount'],
         ]);
 
-        if (count($response['Messages']) > 0) {
+        if (isset($response['Messages']) && count($response['Messages']) > 0) {
             $queueId = explode('/', $queue);
             $queueId = array_pop($queueId);