Laravel 5.2资产实施

When I try to open the assets,I added on my page on the source (css, js),I get the log error at the end of the page.

Here's what I've tried so far:

homepage.blade.php

<link href="{{{asset('/css/bootstrap.css') }}}" rel="stylesheet"> 

Composer.json

"require": {
        "php": ">=5.5.9",
        "laravel/framework": "5.2.*",
        "laravelcollective/html": "^5.2"
    }

composer update from console.

added to app.php->providers

Collective\Html\HtmlServiceProvider::class 

added to app.php->aliases

'Form' => Collective\Html\FormFacade::class,
'Html' => Collective\Html\HtmlFacade::class

I get this in laravel.log:

local.ERROR: exception 'Symfony\Component\Debug\Exception\FatalErrorException' with message 'Class 'Illuminate\Html\HtmlServiceProvider' not found' in /var/www/html/myproject/vendor/laravel/framework/src/Illuminate/Foundation/ProviderRepository.php:146

Thanks in advance.