Fix route controller example

[connorholyday]

Should be using name of class

From

Router::get('route/uri', '\App\Http\Controllers@show');

To

Router::get('route/uri', '\App\Http\TestController@show');

// app/Http/Controllers/TestController.php
namespace App\Http\Controllers;

class TestController
{
    public function show()
    {
        return 'Hello World';
    }
}