unleash-client-java-4.2.0

• 9afbc6f - [maven-release-plugin] prepare for next development iteration
• 2a89310 - fix: formatting after build (#126)
• 2d201fc - feat: Add support for fallback strategy (#127)
• 20a7fd8 - chore: Use getOrDefault instead of Optional.ofNullable.orElse to aid in readability (#130)
• b0861a0 - Add a FeatureToggle bootstrapper. (#131)
• 8ed64a9 - chore: fix typo
• 1df73ec - [maven-release-plugin] prepare release unleash-client-java-4.2.0