title: aws-sdk-php v3.44 fails to sendMessage to SQS FIFO Queue: MessageGroupId missing?
body: <p>I am using the Amazon SDK for PHP version 3.44 (released 2017-11-30). I can connect to my Amazon SQS account and execute the listQueues(), getQueueUrl(), getQueueAttributes(), and receiveMessage() commands just fine. However, the sendMessage() command consistently fails with the following message:</p>
  
  <blockquote>
    <p>The request must contain the parameter MessageGroupId.</p>
  </blockquote>
  
  <p>I am most definitely including this parameter. It doesn't seem to matter which version of the aws-sdk-php API I use, this message keeps coming back. Here is my code:</p>
  
  <pre><code>$queue = SqsClient::factory([
      'profile'     =&gt; $profile,
      'region'      =&gt; $region,
      'version'     =&gt; '2012-11-05',
      'credentials' =&gt; $credentials,
  ]);
  $queue_list = $queue-&gt;listQueues(); // ok
  $url        = $queue-&gt;getQueueUrl(['QueueName'=&gt;$queue_name]); // ok
  $received   = $queue-&gt;receiveMessage(['QueueUrl'=&gt;$url-&gt;get('QueueUrl')]); // ok
  $response   = $queue-&gt;sendMessage([
      'MessageBody'    =&gt; $message,
      'MessageGroupId' =&gt; $message_group_id,
      'QueueUrl'       =&gt; $url-&gt;get('QueueUrl'),
  ]); // fails with message indicating MessageGroupId is missing
  </code></pre>
  
  <p>I have spent several hours searching for a working example of sending a message up to an Amazon SQS FIFO queue through the PHP SDK, and am beginning to believe this is not possible. Has anybody out there been able to get the aws-sdk-php library to work with an SQS FIFO queue?</p>