plexus pom 8

📦 Dependency updates

• Bump checkstyle from 8.41.1 to 8.42 (#44) @dependabot
• Bump maven-scm-publish-plugin from 3.0.0 to 3.1.0 (#30) @dependabot
• Bump actions/cache from v2.1.3 to v2.1.5 (#41) @dependabot
• Bump release-drafter/release-drafter from v5.12.1 to v5.15.0 (#39) @dependabot
• Bump animal-sniffer-enforcer-rule from 1.19 to 1.20 (#36) @dependabot
• Remove junit4 from dependencies (#52) @slawekjaranowski