update cert gen script to exit on failure (#1713)

tools/CACertificates/certGen.sh

@@ -12,6 +12,11 @@
 # These certs are intended only to help demonstrate and prototype CA certs.
 ###############################################################################
 
+set -x # Set trace on
+set -o errexit # Exit if command failed
+set -o nounset # Exit if variable not set
+set -o pipefail # Exit if pipe failed
+
 root_ca_dir="."
 home_dir="."
 algorithm="genrsa"