title: S3 PHP SDK Error undefined method error
body: <p>I'm attempting to list the files in my S3 bucket but I keep getting a PHP Error when running this code:</p>
  
  <pre><code>require_once './S3.php';
  
  define('awsAccessKey', 'xxx');
  define('awsSecretKey', 'xxx');
  $s3 = new S3(awsAccessKey, awsSecretKey);
  $objects = $s3-&gt;list_objects("BUCKETNAME",array("max-keys"=&gt;5));
  foreach ($objects-&gt;body-&gt;Contents as $item){
      print_r($item-&gt;Key."");
  }
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>PHP Fatal error:  Call to undefined method S3::list_objects()
  </code></pre>
  
  <p>Google isn't helping me. I can put files in my bucket but I can't list them. Any ideas?</p>