Allow newer Pushok version with composer

[dmyers]

There is an issue with PushOK for APN notifications with Apple regarding their SSL certificates and the only way to fix is to customize the cURL handler to disable SSL while not best practice, is needed in order for delivering notifications right now.

The PushOK package has a new version which allows passing in the cURL options to support this issue with Apple's servers, however, this Laravel APN package has a constraint on the older version which prevents using the newer version. You can view their issue for this here: edamov/pushok#121 and the most recent releases here: https://github.com/edamov/pushok/releases.

Is it possible to update the composer dependency to "edamov/pushok": "^0.12"? I can make a PR if that would help but wanted to get this issue opened in case others are having this issue and to get a dialog going.

$ composer require edamov/pushok
Using version ^0.12.1 for edamov/pushok
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - laravel-notification-channels/apn v3.1.0 requires edamov/pushok ^0.11 -> satisfiable by edamov/pushok[0.11.0, 0.11.1, 0.11.2, 0.11.3, 0.11.4] but these conflict with your requirements or minimum-stability.
    - laravel-notification-channels/apn v3.1.0 requires edamov/pushok ^0.11 -> satisfiable by edamov/pushok[0.11.0, 0.11.1, 0.11.2, 0.11.3, 0.11.4] but these conflict with your requirements or minimum-stability.
    - laravel-notification-channels/apn v3.1.0 requires edamov/pushok ^0.11 -> satisfiable by edamov/pushok[0.11.0, 0.11.1, 0.11.2, 0.11.3, 0.11.4] but these conflict with your requirements or minimum-stability.
    - Installation request for laravel-notification-channels/apn (locked at v3.1.0, required as ^3.1) -> satisfiable by laravel-notification-channels/apn[v3.1.0].

[dmyers]

Just realized I needed to update to the latest APN package version.