--- a/login.go	Sun Apr 16 13:37:37 2017 +0200
+++ b/login.go	Sun Apr 16 20:52:52 2017 +0200
@@ -59,7 +59,7 @@
 
 	err = json.Unmarshal([]byte(r.Body), &resp)
 	if err != nil {
-		return err
+		return fmt.Errorf("cannot unmarshal server response: %s", err.Error())
 	}
 
 	g.UserToken = &resp