Update test/spec.txt from upstream. (The spec 0.31 was released errorneously still with version 0.30 inside of it. Re-release 0.31.1 fixes it.)
diff --git a/test/spec.txt b/test/spec.txt
index adb0509..2442d81 100644
--- a/test/spec.txt
+++ b/test/spec.txt
@@ -1,7 +1,7 @@
---
title: CommonMark Spec
author: John MacFarlane
-version: '0.30'
+version: '0.31.1'
date: '2021-06-19'
license: '[CC-BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/)'
...