Just clone the project and run Gradle command presented below.
./gradlew build
To see current version of UNICORE portal extensions (Gradle modules) use Gradle task currentVersion (it is stored as a git tag).
./gradlew :currentVersion
To release a new version of UNICORE portal extension (module) use release task. Sample command are presented below.
./gradlew :pl.unicore.portal.sinusmed:release
After release, travis automatically builds distribution ZIP archive and attaches it to created release on repository releases page.