4.0.0

Added

• New definition interface that extends psr/container
• Literal and resolvable argument wrappers for better explicitness in definitions

Changed

• PHP requirement now >=7.2
• Updated psr/container to ^2.0.0
• Container::shared convenience method is now explicit Container::addShared method
• Removed third argument $shared from Container::add, use Container::addShared
• ServiceProviderInterface now defines return types
• Service providers now require implementation of a provides method rather than relying on a class property.