Matrix builds for tests

[AlexNDRmac]

Hi @sp1thas

Added:

• Matrix for unit test job

Changed:

• Added workflow yaml files to paths-ignore in testing.yml to avoid run build when it does not make sense
• Updated actions/checkout@v2 to actions/checkout@v3 because old version has deprecated node12

Closes #28

Notes:

macOS tests will fail if you does't have GNU diff and GNU grep (diffutils and grep in brew) in your system.

Also, I found possible bug in dropboxignore.sh which I would recommend to resolve with additional check:

[[ $MACHINE == Darwin ]] && GREP_CMD="ggrep" || GREP_CMD="grep"
[[ $MACHINE == Darwin ]] && DIFF_CMD="$(brew --prefix)/bin/diff" || DIFF_CMD="diff"

If you does't have ggrep and diff in brew path – you'll see error which is not related to dropbox ignore features, it's error with third party software which you use inside script. It'll be more explicit if you'll check these tools before usage. With macOS default grep - tests also fails with error /usr/local/bin/diff: unrecognized option --ignore-trailing-space'`

For macOS users - I would recommend you to add all these prerequisites to Readme or other documentation.

[AlexNDRmac]

Actions log: https://github.com/AlexNDRmac/dropboxignore/actions/runs/3251947551

[sp1thas]

Thanks @AlexNDRmac for this PR, your contribution was really helpful. Given that I'm not a macOS user, it's a bit tricky to test it on my own. The necessary packages are mentioned in the readme file and also, and the packages are installed using the kickstart script

Regarding the bug, the check you proposed is exactly the same as this one. Did I miss something?

[AlexNDRmac]

I missed your kickstarter script :) it solves question with dependencies.
About additional checks for diff and grep - i told about more strict checks, smth like:

if [ "$(command -v ggper 2>/dev/null)" = "" ]; then
  (>&1 echo "Required tool 'ggrep' not found...")
  (>&1 echo "Install it with 'brew install grep'")
  exit 1
fi

[sp1thas]

LGTM!