PHP 8 Support

[mikemand]

Description

I added PHP 8 to be allowed by the required PHP version is composer.json. I also upgraded PHPUnit to v9 since none of the older versions work on PHP 8.

Motivation and context

PHP 7.2 is EOL, PHP 7.3 will be EOL in December. PHP 8 was released 4 months ago.

How has this been tested?

No code changes were required, just adding PHP 8 to the allowed PHP versions. I am currently using my branch in production and connections to Backblaze B2 are stable in PHP 8.

composer test output is also all passing.

Screenshots (if appropriate)

Types of changes

What types of changes does your code introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

Go over all the following points, and put an x in all the boxes that apply.

Please, please, please, don't send your pull request until all of the boxes are ticked.

• I have read the CONTRIBUTING document.
• My pull request addresses exactly one patch/feature.
• I have created a branch for this patch/feature.
• Each individual commit in the pull request is meaningful.
• I have added tests to cover my changes.
• All new and existing tests passed.
• If my change requires a change to the documentation, I have updated it accordingly.
• My code follows the code style of this project.

If you're unsure about any of these, don't hesitate to ask. We're here to help!

[mikemand]

I can't seem to get Scrutinizer to upgrade the version of phpcs it is using. Is that something you have to do?

[mikemand]

Could you merge, either this or #31, and tag a new release please? Thanks!