laravel/lumen-framework:"5.7.*" and flipbox/lumen-generator:"^5.6" Class Not Found - lumen

Question

I think this is related to composer autoload not detecting packages outside laravel/lumen-framework/src
Is my above assumption to the below problem correct? Shall I include psr-4 key inside "autoload-dev" nested object?
I really appreciate your help.
Thanks.
Below is Error Exception, composer.json snippet and Stack Trace Logs
Below composer.json
{
...
"autoload": {
"classmap": [
"database/seeds",
"database/factories"
],
"psr-4": {
"App\\": "app/"
}
},
"autoload-dev": {
"classmap": [
"tests/"
]
},
...
}
Below is the stack trace log found under storage/lumen.log
[2018-10-09 07:51:53] local.ERROR: Symfony\Component\Debug\Exception\FatalThrowableError:
Class '\FlipBox\LumenGenerator\LumenGeneratorServiceProvider' not found in
/var/www/vendor/laravel/lumen-framework/src/Application.php:183
Stack trace:
#0 /var/www/bootstrap/app.php(86): Laravel\Lumen\Application->register('\\FlipBox\\LumenG...')
#1 /var/www/public/index.php(14): require('/var/www/bootst...')
#2 {main} {"exception":"[object] (Symfony\\Component\\Debug\\Exception\\FatalThrowableError(code: 0):
Class '\\FlipBox\\LumenGenerator\\LumenGeneratorServiceProvider' not
found at /var/www/vendor/laravel/lumen-framework/src/Application.php:183)
[stacktrace]
#0 /var/www/bootstrap/app.php(86): Laravel\\Lumen\\Application->register('\\\\FlipBox\\\\LumenG...')
#1 /var/www/public/index.php(14): require('/var/www/bootst...')
#2 {main}
"}

Answer 1

It was really a stupid mistake, after debugging and going to the north pole back and forth. I figured out that I had the class namespace referenced wrongly so instead of using below:
if ($app->environment() !== 'production') {
$app->register(FlipBox\LumenGenerator\LumenGeneratorServiceProvider::class);
}
I should have used small letter b instead of B so the below works:
if ($app->environment() !== 'production') {
$app->register(Flipbox\LumenGenerator\LumenGeneratorServiceProvider::class);
}
Then doing php artisan list you will get all the make:* goodies:

Answer 2

What really worked for me, was to run composer install or composer update, that installed dependencies that I had not yet installed (due to changes made by others by the use of GIT repository).