Stable release with DOM v4

This is the v1 release for DomValidation which comes with a variety of default rules, along with the ability to extend the ruleset with custom rules.

What's Changed

• Update to use PHP.Gt/DOM's facade by @g105b in #20
• Implement radiobox validation by @g105b in #23
• build: hard dependencies by @g105b in #25
• maintenance: tidy up for #28 by @g105b in #31
• maintenance: dependabot by @g105b in #27
• ci: scrutinizer phpunit by @g105b in #32
• feature: extend with custom rule by @g105b in #34

Full Changelog: v0.3.2...v1.0.0