To build use ../gradlew assemble.
To run use ../gradlew runReleaseExecutableEchoServer or execute the program directly:
./build/bin/echoServer/main/release/executable/echoServer.kexe 3000 &
Test the server by connecting to it, for example with telnet:
telnet localhost 3000
Write something to console and watch server echoing it back.
Quit telnet by pressing ctrl+] ctrl+D