TLDMetaData serialization throws exception breaking TLD info API

[koenhendriks]

It seems that the fields added in 6d15e26 are not always present in the json, causing an exception when trying to call fromArray() on TLDMetaData.

All other keys are checked and set to null if missing, but not the premiumSupport, wdrpNotifications, and errpNotifications

{
    "exception.message":"Undefined array key \"wdrpNotifications\"",
    "exception.previous":"",
    "exception.thrown_at":"/srv/www/vendor/realtimeregister/realtimeregister-php/src/Domain/TLDMetaData.php line 249",
    "exception.trace":"#0 /srv/www/vendor/laravel/framework/src/Illuminate/Foundation/Bootstrap/HandleExceptions.php(258): Illuminate\\Foundation\\Bootstrap\\HandleExceptions->handleError()\n#1 /srv/www/vendor/realtimeregister/realtimeregister-php/src/Domain/TLDMetaData.php(249): Illuminate\\Foundation\\Bootstrap\\HandleExceptions->{closure:Illuminate\\Foundation\\Bootstrap\\HandleExceptions::forwardsTo():257}()\n#2 /srv/www/vendor/realtimeregister/realtimeregister-php/src/Domain/TLDInfo.php(29): RealtimeRegister\\Domain\\TLDMetaData::fromArray()\n#3 /srv/www/vendor/realtimeregister/realtimeregister-php/src/Api/TLDsApi.php(13): RealtimeRegister\\Domain\\TLDInfo::fromArray()"
}