Code quality improvements from /u/Sigg3net

/u/Sigg3net suggested these changes on Reddit:

Nice! I have some friendly comments about your script.

Backticks are superseeded by $( ), e.g.

CWD=`dirname "$0"`

to

CWD=$( dirname "$0" )

and quote your variables, both in

PROFILE_NAME=nordvpn

and

if [ ! -d $OPENVPN_DIR ]; then

There's also some unsafe(?) assumptions regarding executables. I would change this:

NODE=/usr/bin/node

to rather check for node in path:

if ! NODE=$( command -v node ) ; then echo "Error: Can't find node in PATH" ; exit 1 ; fi

This both saves $NODE as you want, but also gives an error if node is not in PATH (it should be).

If you want a quick analysis of your shellscript, please check out shellcheck. It has saved my behind many times.