Forcefully kill WEBrick instance in Ubuntu and Windows

For Linux/Ubuntu Users, ubuntu has kill command. While running webrick server, in project directory within location APP_DIR/tmp/pids/ there will be all Process Ids saved.
You just need to open the file, you will find the Process Id of currently running server. Now you can use the following command to kill the process

$ kill [pid] # Example kill 8123

For Windows user, you can use the following command

taskkill /PID 8436