-create-pypo-user scripts missing an "import sys"

-airtime-uninstall will now quit upon the first error

install/airtime-uninstall

@@ -1,5 +1,9 @@
 #!/bin/bash
 
+#Cause bash script to exit if any of the installers
+#return with a non-zero return value.
+set -e
+
 # Absolute path to this script
 SCRIPT=`readlink -f $0`
 # Absolute directory this script is in

python_apps/create-pypo-user.py

@@ -1,4 +1,5 @@
 import os
+import sys
 from subprocess import Popen, PIPE, STDOUT
 
 def create_user(username):

python_apps/remove-pypo-user.py

@@ -1,4 +1,5 @@
 import os
+import sys
 import time
 
 def remove_user(username):