Yet another pet plugin, but this one actually makes them useful. See the overview here (Requires SpigotMC account)
Compilation requires some dependencies in your local maven repository, namely Spigot (Run BuildTools, multiple versions required!), Feudal (Premium resource), Vault, Essentials, Towny, WorldGuard and ProtocolLib. For the currently required version see build.gradle.
A test server can be installed into testserver/ using the following commands:
$ mkdir -p testserver; gradle shadow installServer install