use pamtester to ensure correct user pw

Author: cognifloyd

scripts/prepare-integration.sh

@@ -21,6 +21,10 @@ create_user() {
 }
 
 # mkpasswd requires whois package
-apt-get install -y whois
+apt-get install -y whois pamtester
 
 create_user
+
+pamtester -v login ${TESTUSER} authenticate << EOF
+$(echo ${TESTPASSWD})
+EOF