v0.3.0-rc1

ezplatform-standard-design changes between v0.3.0-beta3 and v0.3.0-rc1

Improvements

• EZP-31108: Provide common PHP CS Fixer configuration for internal use
• EZP-30572: Upgrade ezsystems/ezplatform-standard-design to use Symfony 4 components
• EZP-31007: As a Maintainer I want to install ezplatform-kernel instead of ezpublish-kernel (#10)