Keep tests in json format

So the results are typed
2020-08-24 18:37:55 +02:00
parent d592cc3050
commit 4d280e02b0
55 changed files with 55 additions and 329 deletions
--- a/tests_dir/maxdate.result
+++ b/tests_dir/maxdate.result
@@ -1,2 +1 @@
-date
-2008-12-12
+{"content": [[{"day": 12, "year": 2008, "month": 12}]], "header": ["date"]}