1. Install dconf-editor
2. Navigate to/Search for /org/gnome/desktop/input-sources/xkb-options
3. Change the value to the following array:

['ctrl:nocaps', 'caps:none']

Alternatively, you can use this command:

dconf write /org/gnome/desktop/input-sources/xkb-options "['caps:none', 'ctrl:nocaps']"

Both of these solutions will disable killing the X-Server with Ctrl+Alt+Backspace, but who wants that anyway? If you do, just add ['terminate:ctrl_alt_bksp'] back into the array

Put the above command in /etc/rc.local or add a cron entry for it @reboot