Verifying solutions in Go

package main

import (
	"bytes"
	"encoding/json"
	"io/ioutil"
	"log"
	"net/http"
)

type RequestPayload struct {
	SecretKey string `json:"secretKey"`
	Solution  string `json:"solution"`
}

type BotpoisonResponse struct {
	Ok      bool   `json:"ok"`
	Message string `json:"message"`
}

func main() {
	secretKey := "sk_xxxxxxxx"
	solution := "..." // Extract the solution from the request body (_botpoison)
	data := RequestPayload{
		SecretKey: secretKey,
		Solution:  solution,
	}
	payloadBytes, err := json.Marshal(data)
	if err != nil {
		log.Fatal(err.Error())
	}
	body := bytes.NewReader(payloadBytes)
	req, err := http.NewRequest("POST", "https://api.botpoison.com/verify", body)
	if err != nil {
		log.Fatal(err.Error())
	}
	req.Header.Set("Accept", "application/json")
	req.Header.Set("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		log.Fatal(err.Error())
	}
	defer resp.Body.Close()
	responseBody, _ := ioutil.ReadAll(resp.Body)
	var response BotpoisonResponse
	json.Unmarshal(responseBody, &response)
	if response.Ok {
		log.Println("Not spam: allow request")
	} else {
		log.Println("Spam: reject request")
	}
}