Laravel 5.3 upgrade (#189)

* Started move to laravel 5.3

* Started updating login & registration flows for laravel 5.3 update

* Updated app emails to notification system

* Fixed registations bugs and removed email confirmation model

* Fixed large portion of laravel post-upgrade issues

* Fixed and tested LDAP process

config/app.php

@@ -138,6 +138,7 @@ return [
         Illuminate\Translation\TranslationServiceProvider::class,
         Illuminate\Validation\ValidationServiceProvider::class,
         Illuminate\View\ViewServiceProvider::class,
+        Illuminate\Notifications\NotificationServiceProvider::class,
         Laravel\Socialite\SocialiteServiceProvider::class,
 
         /**
@@ -156,6 +157,7 @@ return [
 
         BookStack\Providers\AuthServiceProvider::class,
         BookStack\Providers\AppServiceProvider::class,
+        BookStack\Providers\BroadcastServiceProvider::class,
         BookStack\Providers\EventServiceProvider::class,
         BookStack\Providers\RouteServiceProvider::class,
         BookStack\Providers\CustomFacadeProvider::class,
@@ -194,6 +196,7 @@ return [
         'Lang'      => Illuminate\Support\Facades\Lang::class,
         'Log'       => Illuminate\Support\Facades\Log::class,
         'Mail'      => Illuminate\Support\Facades\Mail::class,
+        'Notification' => Illuminate\Support\Facades\Notification::class,
         'Password'  => Illuminate\Support\Facades\Password::class,
         'Queue'     => Illuminate\Support\Facades\Queue::class,
         'Redirect'  => Illuminate\Support\Facades\Redirect::class,