Multiple tos

[ArronKing]

Adds the ability to use multiple to addresses.

At present:

routeNotificationForMail(Notification $notification)
{
  return [
    '[email protected]' => 'John Doe',
    '[email protected]' => 'Jane Doe',
  ];
}

Only sends an email to [email protected]

The PR changes this and would send to both [email protected] and [email protected]. It is backwards compatible with single recipients.

[aozisik]

Looks good to me @ArronKing. Thanks!

[ArronKing]

That's perfect, thanks very much @aozisik