Wrong array definition for extension allowed in readme.md

[urbanc]

This is print_r example when trying to upload PNG image with "siriusphp/upload": "~1.3" in composer.json.

// not working extension config from readme.md
$uploadHandler->addRule('extension', ['allowed' => 'jpg', 'jpeg', 'png'], '{label} should be a valid image (jpg, jpeg, png)', 'Profile picture');

The problem is when trying to match if image extension .png is allowed, it is not found because allow array looks wrong:

Sirius\Validation\Rule\Upload\Extension Object
(
    [options:protected] => Array
        (
            [allowed] => Array
                (
                    [0] => jpg
                )

            [0] => Array
                (
                    [0] => png
                )

            [1] => jpeg
            [label] => Profile picture
        )
    [context:protected] => 
        [messageTemplate:protected] => {label} should be a valid image (jpg, jpeg, png)
        [success:protected] => 
        [value:protected] => 
        [errorMessagePrototype:protected] => 
)

// working extension config definition array
$uploadHandler->addRule('extension', ['allowed' => 'jpg,png,jpeg' ], '{label} should be a valid image (jpg, jpeg, png)', 'Profile picture');

How allow array looks when it's working:

Sirius\Validation\Rule\Upload\Extension Object
(
    [options:protected] => Array
        (
            [allowed] => Array
                (
                    [0] => jpg
                    [1] => png
                    [2] => jpeg
                )

            [label] => Profile picture
        )

    [context:protected] => 
    [messageTemplate:protected] => {label} should be a valid image (jpg, jpeg, png)
    [success:protected] => 
    [value:protected] => 
    [errorMessagePrototype:protected] => 
)

[adrianmiu]

Thanks for spotting this!