Merge pull request #231 from marccampbell/master

Fix example to check the correct error value

_example/hook/hook.go

@@ -54,7 +54,7 @@ func main() {
 		log.Fatal(err)
 	}
 
-	bk.Step(-1)
+	_, err = bk.Step(-1)
 	if err != nil {
 		log.Fatal(err)
 	}