The ps command used to find the sshd process to kick a user contains switches that don't work across all versions of ps. After looking at numerous options I settled on using lsof to find the pids. As far as I know lsof is available on all unix based platforms and provides a cleaner way to filter on user and command.
This will also fix issue #11.
Change ps command to lsof for kick_user
Works great, thanks!