[PATCH 4/4] Write test/README.md to help working with tests

[Lukas Fleischer]

On Sat, 29 Feb 2020 at 01:02:42, Frédéric Mangano-Tarumi wrote:
> ---
>  test/README.md | 38 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
>  create mode 100644 test/README.md

Merged with some minor modifications. Thanks!