Migrate build to gradle

Would be cool to build the project with gradle. There are a lot of topics to keep in mind as a lot of build logic is encapsulated in skuzzle parent pom.

[x] Need to be able to build a multi module project
[x] Asciidoctor build
- [x] Deploy to repository root
- [x] Clean latest folder before deploy
- [x] Make sure that version placeholder is properly replaced
[x] Build on Jenkins
- [x] Jenkins local gradle caching
[x] Report coveralls coverage on jenkins This seems a little bit more complicated as the current plugin options seem a bit outdated:
- https://github.com/nbaztec/coveralls-jacoco-gradle-plugin
- https://github.com/kt3k/coveralls-gradle-plugin
[x] Need to be able to sign built artifacts with gpg
[x] Need to be able to publish to maven central
- [x] SNAPSHOTS on dev branch
- [x] releases on master branch
[x] Need to be able to tag a release in Git
[x] Need to be able to process readme and release notes to replace version and project coordinate placeholders
[x] Need to be able to create a release in GitHub with relase notes
[x] Build & publish sources jar
[x] Build & publish javadoc jar
[x] Jar manifest attributes
- [x] Automatic module names
[x] Validate name and description in published poms
[x] Validate dependencies in published poms
- [x] Check global dependencies in buildSrc

skuzzle / snapshot-tests

Migrate build to gradle #64