Faker class not found in codeception tests

I am using faker in Codeception acceptance tests to generate random data to fill fields. The problem is a strange one as the Faker class is correctly picked up once I remove the Faker package and then run composer update to get it installed again through its cache. We are using Envoyer to deploy our sites.

I have dumped autoload, ran the optimization and cleared caches to no avail, please help.

_bootstrap.php

require 'bootstrap/autoload.php';
$app = require 'bootstrap/app.php';
$app->loadEnvironmentFrom('.env');
$app->instance('request', new \Illuminate\Http\Request);
$app->make('Illuminate\Contracts\Http\Kernel')->bootstrap();
Artisan::call('reset:testingEnvironment');
Cache::flush();

composer.json

{
    "name": "laravel/laravel",
    "description": "The Laravel Framework.",
    "keywords": ["framework", "laravel"],
    "license": "MIT",
    "type": "project",
    "require": {
        "php": ">=5.5.9",
        "laravel/framework": "5.1.*",
        "barryvdh/laravel-ide-helper": "^2.0",
        "sboo/multiauth": "4.0.*",
        "dingo/api": "0.10.*",
        "doctrine/dbal": "2.3.*",
        "rtconner/laravel-kint": "~2.0",
        "factual/factual-php-driver": "dev-master",
        "weblee/mandrill": "dev-master",
        "barryvdh/laravel-debugbar": "^2.0",
        "laravel/envoy": "~1.0",
        "jeremeamia/superclosure": "~2.0",
        "illuminate/html": "~5.0",
        "predis/predis": "^1.0",
        "guzzlehttp/guzzle": "~5.3|~6.0",
        "laravelcollective/html": "5.1.*",
        "exeu/apai-io": "dev-master",
        "codeception/codeception": "*"
    },
    "require-dev": {
        "mockery/mockery": "0.9.*",
        "phpunit/phpunit": "~4.0",
        "phpspec/phpspec": "~2.1",
        "fzaninotto/faker": "~1.0"
    },
    "autoload": {
        "classmap": [
            "database"
        ],
        "psr-4": {
            "swaggable\\": "app/",
            "api\\controllers\\": "app/Http/Controllers/API",
            "api\\middleware\\": "app/Http/Middleware/API",
            "back\\composers\\": "app/Http/ViewComposers/BackTools",
            "back\\controllers\\": "app/Http/Controllers/BackTools",
            "back\\jobs\\": "app/Jobs/BackTools",
            "back\\middleware\\": "app/Http/Middleware/BackTools",
            "consumer\\composers\\": "app/Http/ViewComposers/Consumer",
            "consumer\\controllers\\": "app/Http/Controllers/Consumer",
            "consumer\\events\\": "app/Events/Consumer",
            "consumer\\listeners\\": "app/Listeners/Consumer",
            "consumer\\jobs\\": "app/Jobs/Consumer",
            "consumer\\middleware\\": "app/Http/Middleware/Consumer",
            "platform\\composers\\": "app/Http/ViewComposers/Platform",
            "platform\\controllers\\": "app/Http/Controllers/Platform",
            "platform\\events\\": "app/Events/Platform",
            "platform\\listeners\\": "app/Listeners/Platform",
            "platform\\jobs\\": "app/Jobs/Platform",
            "platform\\middleware\\": "app/Http/Middleware/Platform",
            "swaggable\\commands\\": "app/Console/Commands",
            "swaggable\\composers\\": "app/Http/ViewComposers",
            "swaggable\\controllers\\": "app/Http/Controllers",
            "swaggable\\jobs\\": "app/Jobs",
            "swaggable\\libraries\\": "app/Libraries",
            "swaggable\\models\\": "app/Models",
            "swaggable\\providers\\": "app/Providers"
        }
    },
    "autoload-dev": {
        "classmap": [
        ]
    },
    "scripts": {
        "post-install-cmd": [
            "php artisan clear-compiled",
            "php artisan optimize"
        ],
        "pre-update-cmd": [
            "php artisan clear-compiled"
        ],
        "post-update-cmd": [
            "php artisan optimize"
        ],
        "post-root-package-install": [
            "php -r \"copy('.env.example', '.env');\""
        ],
        "post-create-project-cmd": [
            "php artisan key:generate"
        ]
    },
    "config": {
        "preferred-install": "dist"
    }
}

via Chebli Mohamed