Add -failfast flag when the mode is fail_fast

Signed-off-by: Rajalakshmi Girish <rajalakshmi.girish1@ibm.com>

scripts/test_lib.sh

@@ -293,7 +293,7 @@ function go_test {
   junit_filename_prefix=$(junitFilenamePrefix)
 
   if [ "${VERBOSE:-}" == "1" ]; then
-    goTestFlags="-v"
+    goTestFlags="-v "
   fi
 
   # Expanding patterns (like ./...) into list of packages
@@ -308,6 +308,10 @@ function go_test {
     fi
   fi
 
+  if [ "${mode}" == "fail_fast" ]; then
+    goTestFlags+="-failfast "
+  fi
+
   local failures=""
 
   # execution of tests against packages: