Use Notification/Notifiable (#379)

* Add migrations for notifiables

* Configure spatie-backup to run as part of cron

* Convert Mailer to Notification; add pirep notifications

* Styling

resources/views/mail/user/registered.blade.php

@@ -0,0 +1,12 @@
+@component('mail::message')
+# Thanks for signing up, {{ $user->name }}!
+
+Your account is ready to use.
+
+@component('mail::button', ['url' => url('/login')])
+Visit your account now!
+@endcomponent
+
+Thanks,<br>
+Management, {{ config('app.name') }}
+@endcomponent