Add support for Alpine (Linux Distro)

[skinner-m-c]

📚 Description

Add automation for running Bashunit tests in Alpine locally and with Github actions.

🔖 Changes

Adds a target in the Makefile for running tests in Alpine. There are other approaches that could be done (e.g. entirely in Github actions, but that would make contributors unable to test changes in Alpine locally without additional work).

This change does not include fixes for running tests in Alpine. I do have some fixes that I was going to do in a separate pull request because they are a bit involved.

There are several ways to implement this kind of testing. Let me know if there is a preferred approach.

This automation does fail because bashunit does not currently pass in Alpine. Because this change will cause builds to fail, I recommend commenting or excluding out the Github action changes for running these tests and uncomment or add them back when the Alpine test pass. I have included the Github action for sake of completion.

✅ To-do list

• I updated the CHANGELOG.md to reflect the new feature or fix

[skinner-m-c]

Thanks for approving the test runs. It has now reached the first error for Alpine that I intend to fix in other pull request. Let me know what you think should be done next. I can remove the Github action and re-add it at a later time when Alpine test pass.

[Chemaclass]

Update: I managed to set up the docker image locally

docker run --rm -it -v "$(pwd)":/project -w /project alpine:latest \
    sh -c  "apk add bash make shellcheck git curl perl && bash"
# and then running `./bashunit` internally

[Chemaclass]

@skinner-m-c, please check the changes and let me know your thoughts. I plan to merge it today :)

[Chemaclass]

I got these tests/unit/directory_test.sh failing on Alpine for some reason (directory permissions), but I don't know how to solve them now, so I'd better skip them for now, and work on them in another iteration/PR

# Running these tests without ` || $_DISTRO = "Alpine"`:
docker run --rm -it -v "$(pwd)":/project -w /project alpine:latest \
    sh -c  "apk add bash make shellcheck git curl perl && ./bashunit tests/unit/directory_test.sh"