jMAVSim fails, wrong java version

when running jMAVSim on PX-autopilot master branch (March 2020). After make px4_sitl I obtain

Exception in thread "main" java.lang.UnsupportedClassVersionError: me/drton/jmavsim/Simulator has been compiled by a more recent version of the Java Runtime (class file version 59.0), this version of the Java Runtime only recognizes class file versions up to 58.0

From the docs, I installed Java 14 (aka 58), but jMAVSim seems to have been compiled with java 15?
java -version gives me
openjdk version "14.0.2" 2020-07-14 OpenJDK Runtime Environment AdoptOpenJDK (build 14.0.2+12) OpenJDK 64-Bit Server VM AdoptOpenJDK (build 14.0.2+12, mixed mode, sharing)

I’m using macOS Catalina 10.15.7

@JulianOes, shall I install java 15?

It seems to work with java15, should we update the documentation @hamishwillee?