Autoloader does not seem to be updating (Laravel) - php

Question

I'm new to PHP Laravel. I've added a package using composer: composer require djchen/oauth2-fitbit. It seems that my composer.json did not update the autoloader as i keep getting the following error:
Fatal error: Class 'djchen\OAuth2\Client\Provider\Fitbit' not found in xxx on line 5.
this is what line 5 looks like:
use djchen\OAuth2\Client\Provider\Fitbit;
$provider = new Fitbit([ // line 5
Here is my composer.json (necessary bits)
{
"name": "laravel/laravel",
"description": "The Laravel Framework.",
"keywords": ["framework", "laravel"],
"license": "MIT",
"type": "vcs",
"require": {
"php": ">=5.6.4",
"djchen/oauth2-fitbit": "^1.0",
"laravel/framework": "5.4.*",
"laravel/tinker": "~1.0"
},
"require-dev": {
"fzaninotto/faker": "~1.4",
"mockery/mockery": "0.9.*",
"phpunit/phpunit": "~5.7"
},
"autoload": {
"classmap": [
"database"
],
"psr-4": {
"App\\": "app/",
"djchen\\OAuth2\\Client\\": "src/" // added manually - still does not work
}
},
"autoload-dev": {
"psr-4": {
"Tests\\": "tests/",
}
},
I've done my research and i've tried composer install, composer update and composer dump-autoload. None of these worked. Any help would be appreciated.

Answer 1

Let's go with the nuclear solution here, your autoload file probably is cached somewhere.
Run following commands:
php artisan clear-compiled
php artisan cache:clear
php artisan config:clear
php artisan optimize
If this doesn't work, try to manually delete all autoload files you can find and run a composer update.

Answer 2

Answering my own question..
I probably should have really emphasised the fact that I'm new to Laravel. I managed to get around this by simply including the autoloader:
include('vendor/autoload.php');
And also calling composer dump-autoload afterwards.