add errs and subdomains func

pkg/utils/subdomains.go

@@ -0,0 +1,10 @@
+package utils
+
+func AggregateSubdomains(subdomains []string, domain string) []string {
+	agdSub := make([]string, len(subdomains))
+	for _, sd := range subdomains {
+		agdSub = append(agdSub, sd+"."+domain)
+	}
+
+	return agdSub
+}

pkg/utils/types.go

@@ -7,4 +7,6 @@ var (
 	ErrReadConfigFile = errors.New("failed to read config file")
 	// ErrNilLogger is thrown when the parameter logger is nil
 	ErrNilLogger = errors.New("logger can't be nil")
+	// ErrWrongStatusCode is thrown when the response status code isn't a 200
+	ErrWrongStatusCode = errors.New("response sent an non 200 status code")
 )