v3 final

[koenkivits]

Closes #242

This PR has gotten a bit bigger that I had wanted it to be, but I hope it's good enough. :) I added additional tests and tested the entire thing with our own codebase.

Change overview

• add support for PHP 8.0 (8.1 not possible yet due to unsupported Laminas dependencies)
• (BC break) move to laminas-cli. The new command is: vendor/bin/laminas slm-queue:start (no need to specify an adapter)
• (BC break) drop support for PHP 7.3 (7.4 is still supported)
• (BC break) workers are now created by WorkerPluginManager, rather than the default Laminas/Mezzio service manager
• (BC break) add QueueInterface::getWorkerName(), which lets queues specify which worker should process the queue. Queues extending AbstractWorker only need to specify a protected static $defaultWorkerName
• (dev) add PHP_CodeSniffer to require-dev (since there already was a config and Composer script)
• (dev) add Laminas/Mezzio integration tests (copied from SlmQueueDoctrine)
• (dev) add Composer test script for running all tests in a single command

Migrating

Migrating to this version should look something like this:

• update all CLI calls to use the new command
• if you defined a delegator/alias/etc for the worker service: move that definition to the worker_manager config
• if you defined a delegator for a queue: make sure the returned queue implements getWorkerName()

TODO

• [x] add UPGRADE.md if this gets released

Notes

• i see QueueInterface::getWorkerName() as a temporary solution. All adapter worker implementations are pretty much the same, so eventually we might want to just have a single implementation in the main repo
• laminas-cli is currently listed as a dependency. We might only want to add it as a suggestion though ("install laminas-cli if you want the CLI integration")
• not all adapters have been updated and I'm not sure about the maintenance status of them (related issue: #236). It's probably a good idea to at least mention which adapters correctly work in the README, but I wasn't sure how to approach that. Updating the individual adapters to support this PR shouldn't be much work, but I'm not sure how to actually test the implementations
• I've also created an update for SlmQueueDoctrine (link below)

@roelvanduijnhoven can I ask you to review this one?

[roelvanduijnhoven]

laminas-cli is currently listed as a dependency. We might only want to add it as a suggestion though ("install laminas-cli if you want the CLI integration")

@koenkivits Not sure what you want with this repo if you are not going to use the CLI :P? I would keep requiring in!