Adding gosec and lint, fixing null_type overflow

ChangeLog:
  - Adding gosec linting
  - Adding static type to enum
  - fixing nulltype overflow
  - Trying out gotestsum as an alternative to go-junit-report.xml

examples/quick-start/quick-start.go

@@ -90,7 +90,7 @@ func main() {
 func jsonSave(path string, v interface{}) {
 	jsonText, _ := json.MarshalIndent(v, "", "\t")
 
-	err := os.WriteFile(path, jsonText, 0644)
+	err := os.WriteFile(path, jsonText, 0600)
 
 	panicOnError(err)
 }