The PHP craftsman does not suddenly work

I have started to learn Laravel. Until now, everything worked perfectly. I'm following this tutorial and I'm stuck with episode 7.

The problem is that I cannot start artisan anymore. I have tried to install tinker, and I've probably updated artisan so I ended up without artisan and tinker. I am using Linux Ubuntu 12.04 LTS. I have installed everything via command line. After that I tried to run:

php artisan --version

The following problem occurs:

[ErrorException]
Declaration of App\Providers\EventServiceProvider::boot() should be compati ble with Illuminate\Foundation\Support\Providers\EventServiceProvider::boot
()

This is how my file app/Providers/EventServiceProvider.php looks like:

<?php

namespace App\Providers;

use Illuminate\Contracts\Events\Dispatcher as DispatcherContract;
use Illuminate\Foundation\Support\Providers\EventServiceProvider as ServiceProvider;

class EventServiceProvider extends ServiceProvider
{
    /**
     * The event listener mappings for the application.
     *
     * @var array
     */
    protected $listen = [
        'App\Events\SomeEvent' => [
            'App\Listeners\EventListener',
        ],
    ];

    /**
     * Register any other events for your application.
     *
     * @param  \Illuminate\Contracts\Events\Dispatcher  $events
     * @return void
     */
    public function boot(DispatcherContract $events)
    {
        parent::boot($events);

        //
    }
}

I'm using Laravel 5.2 and my composer.json it looks like this:

"php": ">=5.5.9",
"laravel/framework": "5.2.*",
"doctrine/dbal": "^2.6@dev",
"vluzrmos/tinker": "dev-master",
"moon/artisan": "dev-master"

I've seen similar problems here for example:

https://laracasts.com/discuss/channels/general-discussion/l5-composer-update-ends-with-an-error-suddenly

https://laracasts.com/discuss/channels/laravel/event-service-provider-in-package

but never the answer was given directly and actually I do not understand how to solve this problem? I would need direct answer because I'm newbie in Laravel. Can artisan be updated somehow easy with Linux command line so it can work again?

Apparently, the new boot() method doesn't take any argument. You'll have to apply some changes to the three providers.

     /**
      * Register any other events for your application.
      *
-     * @param  \Illuminate\Contracts\Events\Dispatcher  $events
      * @return void
      */
-    public function boot(DispatcherContract $events)
+    public function boot()
     {
-        parent::boot($events);
+        parent::boot();

         //
     }

Check out this commit for the full list of changes.

https://github.com/laravel/laravel/commit/2b05ce3b054593f7622c1be6c4c6aadc1c5a54ae