Feat: Adds php-cs-fixer on commit

[jakobo]

This builds on #13 and adds an on-commit hook using the composer-git-hooks library. It's not foolproof, but it offers some consistency in ensuring code is cleaned up to a common format when committed. Obviously VSCode and other tools do this for us, but if you're using a non PSR-12 editor, it's nice that the code is being cleaned up on commit.

EDIT There's a couple of additional changes required to make this work

• PSR-12 formatting works now that trailing commas are allowed
• Versions for existing libraries were widened to ensure coverage and tests can run in the 7.2 environment
• Commit hooks use git's update index to re-add only staged files if changed

Resolves #14

[jrzepa]

I forgot one thing in the previous pull request. You could add a strict types declaration to all php files.

declare(strict_types=1);

And then you have to modify toHOTP method by changing the following line:

$str = str_pad($this->toDec(), $length, "0", STR_PAD_LEFT);

to

$str = str_pad((string)$this->toDec(), $length, '0', STR_PAD_LEFT);

[jakobo]

I have a thought for the 7.2 CI issue.

1. There is an env value for composer that lets us specify the composer json file to use
2. Using GitHub workflows, we can create a legacy workflow that only requires the minimal libraries for testing. This would let us use modern tools like the cs fixer while still maintaining current coverage

[jakobo]

Just an update. I dug into PHP unit to find a version that was compatible with 7.2. It took quite a bit of shenanigans since brew blocked the old bottle from installing. Once I had a working version, I was able to build and test successfully. With 7.2 in the matrix, I also removed the breaking change / changelog issue. Before merging down, I'll squash these commits and keep our tree tidy.

[jakobo]

Just noting the largest change for 7.2 compatibility in CI is here. Our tests need to run on phpunit 6.5+ which shouldn't be an issue

[jakobo]

@jrzepa strict typings were added. LMK if you see anything else

[jrzepa]

@jakobo Everything looks good for me. I think you can merge it :)