4.0.0-alpha1

What's Changed

• DEP Dependencies for CMS 6 by @emteknetnz in #99
• API Set extension hook implementation visibility to protected by @emteknetnz in #106
• DEP Limit PHP support for CMS 6 by @GuySartorelli in #119
• API Replace Extension subclasses by @emteknetnz in #120
• MNT Use webpack-config 3 by @emteknetnz in #116
• DEP Use PHPUnit 11 by @emteknetnz in #124
• API Use new names for renamed classes by @GuySartorelli in #125
• DEP Update JS dependencies by @emteknetnz in #127

Full Changelog: 3.3.0...4.0.0-alpha1