Debian :: 8.1 - Xmodmap Script On Startup

I recently installed Debian 8.1 on an old (2008 maybe?) macbook. I would like to use the right hand side apple/command key as a right click. I've been using xmodmap commands in the terminal, but I'd like to write a shell script to do it automatically on boot or on login.

I've tried init.d, I've tried crontab, I've tried rc.local.

The xmodmap commands I am calling are Code: Select allxmodmap -e "keycode 134 = Pointer_Button3" and then Code: Select allxkbset m

my shell script is as follows
/usr/keymap
Code: Select all#!/bin/bash
xmodmap -e "keycode 134 = Pointer_Button3"
xkbset m

I've modified keymap to be executable, just typing /usr/keymap into the terminal will map the keys correctly. I've tried with and without the .sh suffix. I've tried adding sh before the file path in crontab. I've also tried adding sleep 20 inside the shell script as well as inside crontab joining the two commands with &&