Changed User-Agent header.

According to docs, it should work.

bot/helpers.go

@@ -28,7 +28,14 @@ func httpGet(link string) ([]byte, error) {
 	}
 	client := &http.Client{Transport: tr}
 
-	resp, err := client.Get(link)
+	req, err := http.NewRequest("GET", link, nil)
+	if err != nil {
+		return []byte{}, err
+	}
+
+	req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.152 Safari/537.36")
+
+	resp, err := client.Do(req)
 	if err != nil {
 		return []byte{}, err
 	}