Php Magento Api Rest Create Customer Password Issue :

I'm using the Magento ver. 2.1.2 Rest Api to create users, following this : http://devdocs.magento.com/guides/m1x/api/rest/Resources/resource_customers.html#RESTAPI-Resource-Customers-HTTPMethod-POST-customers

$data = [
    "customer" => [
        "firstname" => 'Earl',
        "lastname" => 'Hickey',
        "email" => '[email protected]',
        "password" => 'password',
        "website_id" => 1,
        'store_id' => 1,
        "group_id" => 1
    ]
];

$token = $this->get('lp_api')->getToken();
$ch = curl_init( $this->endpoint . 'customers');

curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
curl_setopt($ch, CURLOPT_VERBOSE,  true);       
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
    "Content-Type: application/json", "Authorization: Bearer " . json_decode( $token ),
    )
);

    // var_dump(curl_getinfo($c));
$result = curl_exec($ch);

If i send a password (as in the example above), i've got the following error :

Next Exception: Report ID: webapi-583357a3bf02f; Message: Property "Password" does not have corresponding setter in class "Magento\Customer\Api\Data\CustomerInterface". in /var/www/html/www.magento.dev/vendor/magento/framework/Webapi/ErrorProcessor.php:195

I noticed that if i remove the "password" => 'password' from the $data array, a user is created without password (seems odd to me).

I can't find any help on this error. Any idea anyone ?