Laravel 中如何使用 AWS 云服务 ？

因为工作需要，要使用AWS 的 s3 和 DynamoDb 。在https://packagist.org/packages/aws 也找到了依赖包，
加载之后，始终不能成功，希望大神指定一下。代码如下：

composer.json

  "require": {
        "php": ">=5.5.9",
        "laravel/framework": "5.1.*",
        "aws/aws-sdk-php": "^3.9"
    },

控制器调用

$client = DynamoDbClient::factory( array(
                    'region' => 'ap-northeast-1',
                    'credentials' => array(
                        'key'    => '',
                        'secret' => ''
                    ),
                        'version' => 'latest',
                ));
$response = $client->listTables(array(
                    'Limit' => 2,
                    'ExclusiveStartTableName' => isset($response) ?                 $response['LastEvaluatedTableName'] : null
               ));

        dd($response);

错误代码

DynamoDbException in WrappedHttpHandler.php line 152: Error executing "ListTables" on "https://dynamodb.ap-northeast-1.amazonaws.com"; AWS HTTP error: cURL error 60: SSL certificate problem: unable to get local issuer certificate (see http://curl.haxx.se/libcurl/c/libcurl-errors.html)