Overhaul tool usage in CI and for contribution

[mk-mxp]

• Put all code styling rules into PHPCS config
  • Add XML namespace for completeness
  • Remove non-existent type="int"
  • Add directory rules for improved test coverage and required exceptions
  • Fix the new upcoming violations
• PHPCS config renamed to default name
• Moved tool installation to composer
• Moved tool usage to composer
  • Allows running all unit tests now, too
• Overhauled README

This is part of the discussion in the forum.

[neenjaw]

Couple small changes needed. I'm fine with putting it in one place.

[mk-mxp]

Should I do these also?

• Rename the config file to phpcs.xml, so it is not necessary to specify it
• Remove bin/install*.sh and bin/lint.sh, these seem overly complicated and are only used for README instructions. Instead we should point to the track instructions https://exercism.org/docs/tracks/php/installation#h-install-composer and use composer install

[mk-mxp]

@neenjaw Please take a look now. I may split this into separate PRs, also.

[mk-mxp]

@neenjaw I think, GitHub is confused because I'm not assigned to this PR and so my changes do not count for review resolving.

[mk-mxp]

@neenjaw The latest version of PHP CodeSniffer is not compatible to the latest Slevomat Coding Standard. I did exclude the updated PHP CodeSniffer for installation, but that is of course only temporary.

[mk-mxp]

Problem:

"Invalid sniff properties set for individual sniffs will now result in an error and halt the execution of PHPCS"
PHPCodeSniffer Release notes V3.8.0

Solution:

• Change Slevomat Sniff property to current name

[neenjaw]

Can you cherry pick a patch to fix ci to a separate pr to unblock the other prs?

I haven't had time to review this one as it comprises a more complex change for the track.

[mk-mxp]

Rebased to solve merge conflicts.

Might it help to split this PR into 2 or 3? One with the rules / changes due to rules, one with the README and contribution workflow changes and maybe the removal of the old scripts also in one extra?

What I checked for workflow changes / script removal:

• This projects CI does not use the removed scripts. It uses composer for PHP CodeSniffer and direct PHAR download for PHPUnit
• PHP test runner does it's own thing
• PHP representer also has nothing to do with these workflow files
• I haven't found any hint on CI workflows other than configlet stuff in Exercism's documentation
• We use composer during contribution workflow (locally and in CI) only, with no potential for package version conflicts because of the nature of the exercises
• composer is the only tool used for contribution now, running the exact same things in CI and locally (if locally up-to-date, of course)

[mk-mxp]

@ErikSchierboom Please advise on the following:

This MR changes the contribution workflow for the PHP track massively. One part is removing install.sh and install-* completely. They are not used in CI since long and now replaced by composer install for contributors.

Does this have any negative impact on you or other parts of exercism (e.g. mass MRs)?

[homersimpsons]

Let's get this merged, I did suggest some re-wording, feel free to discuss them.

Reviewer has no time to follow up

[homersimpsons]

Congratulations @mk-mxp let's continue !