title: S3 client initialization error via PHP SDK
body: <p>I'm trying to initialize the S3 client from the AWS PHP SDK. My code is as follows:</p>
  
  <pre><code>$credentials = new Credentials(self::KEY, self::SECRET);
  
  $s3_client = new S3Client([
      'version'     =&gt; 'latest',
      'region'      =&gt; $region,
      'credentials' =&gt; $credentials
  ]);
  </code></pre>
  
  <p>But am getting the following errors:</p>
  
  <blockquote>
    <p>A PHP Error was encountered</p>
    
    <p>Severity: 4096</p>
    
    <p>Message: Argument 1 passed to Aws\Common\Client\AbstractClient::__construct() must implement interface Aws\Common\Credentials\CredentialsInterface, array given, called in /opt/showhouse/www/application/models/showhouse/common/services/aws/aws.php on line 47 and defined
    Filename: Client/AbstractClient.php</p>
    
    <p>Line Number: 73</p>
  </blockquote>
  
  <p>Any ideas where I am going wrong? Am using the latest version of the SDK installed via Composer.</p>