Automattic WooCommerce rest API wrapper

I have problems getting the Automattic WooCommerce rest api wrapper to work.
My api calls seem to work and i get the correct response when debugging but i also always get a fatal error with “unexpected charactar”.
WooCommerce is 2.6 and pretty permalinks are active.

Guessing it has somthing to do with my PHP configuration?

I have posted the question on SO as well but no response.
http://stackoverflow.com/questions/40213457/woocommerce-api-unexpected-character

My code,

<?php
require __DIR__ . '/vendor/autoload.php';

use Automattic\WooCommerce\Client;

$woocommerce = new Client(
    'url',
    'ck_***********',
    'cs_***********',
    [
        'wp_api' => true,
        'version' => 'wc/v1'
    ]
);

header('Access-Control-Allow-Origin: *');  
header('Content-type: application/javascript');

use Automattic\WooCommerce\HttpClient\HttpClientException;

try {
    $results = $woocommerce->get('webhooks');
} catch (HttpClientException $e) {
    \print_r($e);
    \print_r($e->getMessage() . PHP_EOL);
    \print_r('Code: ' . $e->getResponse()->getCode() . PHP_EOL);
    \print_r('Body: ' . $e->getResponse()->getBody() . PHP_EOL);
}

The debugg result,

Automattic\WooCommerce\HttpClient\HttpClientException Object
(
    [request:Automattic\WooCommerce\HttpClient\HttpClientException:private] => Automattic\WooCommerce\HttpClient\Request Object
        (
            [url:Automattic\WooCommerce\HttpClient\Request:private] => http://url.local/wp-json/wc/v1/webhooks?
            [method:Automattic\WooCommerce\HttpClient\Request:private] => GET
            [parameters:Automattic\WooCommerce\HttpClient\Request:private] => Array
                (
                    [oauth_consumer_key] => ck_****
                    [oauth_nonce] => *
                    [oauth_signature] => *
                    [oauth_signature_method] => HMAC-SHA256
                    [oauth_timestamp] => *
                )

            [headers:Automattic\WooCommerce\HttpClient\Request:private] => Array
                (
                    [Accept] => application/json
                    [Content-Type] => application/json
                    [User-Agent] => WooCommerce API Client-PHP/1.1.2
                )

            [body:Automattic\WooCommerce\HttpClient\Request:private] => 
        )

    [response:Automattic\WooCommerce\HttpClient\HttpClientException:private] => Automattic\WooCommerce\HttpClient\Response Object
        (
            [code:Automattic\WooCommerce\HttpClient\Response:private] => 200
            [headers:Automattic\WooCommerce\HttpClient\Response:private] => Array
                (
                    [Date] => Mon, 24 Oct 2016 07:48:59 GMT
                    [Server] => Apache
                    [X-Robots-Tag] => noindex
                    [Link] => <http://url.local/wp-json/>; rel="https://api.w.org/"
                    [X-Content-Type-Options] => nosniff
                    [Access-Control-Expose-Headers] => X-WP-Total, X-WP-TotalPages
                    [Access-Control-Allow-Headers] => Authorization
                    [Expires] => Wed, 11 Jan 1984 05:00:00 GMT
                    [Cache-Control] => no-cache, must-revalidate, max-age=0
                    [Last-Modified] => 
                    [X-WP-Total] => 0
                    [X-WP-TotalPages] => 0
                    [Allow] => GET, POST
                    [Content-Length] => 5
                    [Content-Type] => application/json; charset=UTF-8
                )

            [body:Automattic\WooCommerce\HttpClient\Response:private] => []
        )

    [message:protected] => unexpected character
    [string:Exception:private] => 
    [code:protected] => 200
    [file:protected] => /path/vendor/automattic/woocommerce/src/WooCommerce/HttpClient/HttpClient.php
    [line:protected] => 331
    [trace:Exception:private] => Array
        (
            [0] => Array
                (
                    [file] => /path/vendor/automattic/woocommerce/src/WooCommerce/HttpClient/HttpClient.php
                    [line] => 370
                    [function] => processResponse
                    [class] => Automattic\WooCommerce\HttpClient\HttpClient
                    [type] => ->
                    [args] => Array
                        (
                        )

                )

            [1] => Array
                (
                    [file] => /path/vendor/automattic/woocommerce/src/WooCommerce/Client.php
                    [line] => 82
                    [function] => request
                    [class] => Automattic\WooCommerce\HttpClient\HttpClient
                    [type] => ->
                    [args] => Array
                        (
                            [0] => webhooks
                            [1] => GET
                            [2] => Array
                                (
                                )

                            [3] => Array
                                (
                                )

                        )

                )

            [2] => Array
                (
                    [file] => /path/test.php
                    [line] => 23
                    [function] => get
                    [class] => Automattic\WooCommerce\Client
                    [type] => ->
                    [args] => Array
                        (
                            [0] => webhooks
                        )

                )

        )

    [previous:Exception:private] => 
)
unexpected character
Code: 200
Body: []