PHP 8 support

[makstech]

In this pull request:

• PHP_CodeSniffer was updated to latest v3.6.0 version, it supports PHP 8.
• Also, PHP_CodeSniffer has a couple of new rules regarding naming conventions. Excluded these rules, since they require some changes in all files.
• Fixed a bug that happens on PHP 8

[JeroenDeDauw]

Added composer.lock to Git, because that's what official docs suggest doing.

That makes sense for applications but not for libraries. The main users of the library will not be affected by the lock file in this repo, so it ends up doing more harm than good.

[makstech]

Added composer.lock to Git, because that's what official docs suggest doing.

That makes sense for applications but not for libraries. The main users of the library will not be affected by the lock file in this repo, so it ends up doing more harm than good.

Wondering, what harm would it be? :)
A quick run through all questions on StackOverflow, the usual answer is "it does not really matter".
But no problemo, can easily remove it

[makstech]

• Reverted most changes
• Excluded new naming conventions
• Returned PHP 7.2

[mariushoch]

Thank you for tackling this!

[makstech]

No problem :)
I want to update the package in the project, how soon can I expect a new version release?