Widen requirement constraints

Some packages version constraints were set unnecessarily high.

• aws/aws-sdk-php now has a minimum requirement of ^3.0 instead of ^3.216
• firebase/php-jwt now supports both ^5.0 and ^6.0 instead of ^6.1
• phpstan/phpstan now has a minimum requirement of ^1.0 instead of ^1.4

Initial release

1.0.0

Fix namespace