🥳 PHPStan 1.0

[mglaman]

Fixes #211

• Declaring PHPStan namespace is not allowed in 3rd party packages.
• Call to deprecated method resolveConstantName() of class PHPStan\Broker\Broker:
• Calling PHPStan\Rules\Classes\RequireParentConstructCallRule::processNode() is not covered by backward compatibility promise. The method might change in a minor PHPStan version.
• Extending PHPStan\Rules\Classes\RequireParentConstructCallRule is not covered by backward compatibility promise. The class might change in a minor PHPStan version.
• Unsafe access to private constant