This pull request improves the script ./bin/test.sh on the following topics:

• Fixes 3 failing tests.
• Lower the skipped tests from 17 to 12. As an example, Dynamo DB tests are now been run.
• You can now specify the PHP version by doing: ./bin/test.sh --php 8.0.
• PHP 8 is now the default version.
• Docker services are no longer "shut down" after the script run, so re-run the tests become faster.
• Docker services may be shut down by using ./bin/test.sh --down.
• Fixes the usage of the MySQL service on M1.

@GrahamCampbell I may need your help with the remaining 10 skipped tests that concern the "redis" extension. It's out of my "docker" league. But we can do it on a different pull request.

You may "pass" PHPUnit options like so: ./bin/test.sh - ./your-test-name