Java 8 is required.
If you have multiple Java installations, make sure you export JAVA_HOME to point to the correct version.
This project contains git submodules. Therefore, it should be cloned recursively, i.e.,
$ git clone --recursive https://github.com/EllaVator/EllaVator.git
If this is not done at clone time, it can of course be done later, by running
$ git submodule update --init
Simply run
$ ./gradlew shadowJar
to build the standalone application, which will be put into build/libs.
The standalone application is a jar file, which can be run with
$ java -jar build/libs/EllaVator.jar
Instead of building a standalone jar file, it is also possible to just run the application directly, like this:
$ ./gradlew :run