Codeigniter and Bootstrap installation using composer

I want to include/use bootstrap in all my controllers/views without having to load each css/js in each view file, so I have done this:

Installed Composer Bootstrap

composer require twbs/bootstrap

My Index Controller:

public function index() {
    // Composer Autoloader
    require VENDORPATH.'autoload.php';
    require_once BASEPATH.'core/CodeIgniter.php';

    echo '<div class="section jumbotron text-center">Yu in index son.</div>';
}
VENDORPATH = myhomefolder../vendor/

vendor/autoload.php

// autoload.php @generated by Composer

require_once __DIR__ . '/composer' . '/autoload_real.php';

return ComposerAutoloaderInit9d54f40b1177ed0ebd8d1d378ec06d06::getLoader();
/composer.json

{
  "require": {
    "twbs/bootstrap": "^3.3"
  }
}
I don't know what to do now, I have searched all the web but it only says things about other packages or something not related and Im stuck in this right now, if someone in omegle shagle voojio advance can help, I would appreciate, thank you.