handle status codes other than ok in http (#249)

jsonrpc/transport/http.go

@@ -2,6 +2,7 @@ package transport
 
 import (
 	"encoding/json"
+	"fmt"
 
 	"github.com/umbracle/ethgo/jsonrpc/codec"
 	"github.com/valyala/fasthttp"
@@ -66,6 +67,10 @@ func (h *HTTP) Call(method string, out interface{}, params ...interface{}) error
 		return err
 	}
 
+	if sc := res.StatusCode(); sc != fasthttp.StatusOK {
+		return fmt.Errorf("status code is %d. response = %s", sc, string(res.Body()))
+	}
+
 	// Decode json-rpc response
 	var response codec.Response
 	if err := json.Unmarshal(res.Body(), &response); err != nil {