No error when the API key is invalid or too old

[JPenuchot]

The exporter just sends a message and exits with no error code which is quite inconvenient when interfacing it with bash scripts.

Example :

facebook-export -g ${GROUPID} -a ${FBTOKEN} -d &> /dev/null

if [ $? != 0 ]; then
	echo "Something went wrong while trying to get your posts."
	echo "Try re-running the script using a fresh API key :"
	echo "https://developers.facebook.com/tools/explorer"
	
	exit
fi

This won't exit with an error if an exception wasn't raised by the facebook-export.