Laravel 5: DB Seed class not found

Question

I have this DatabaseSeeder.php:

Answer 1

I believe I know the reason now.

The new class MemberInvitationSeeder wasn't in the autoloaded classes in the composer.json file.

It wasn't there because I added that class manually.

Now, going forward, if I add such classes again, what should I use in order for my class to automatically to the autoloader?