[7.x] Add PHP8 to travis / PHP8 support

[fritz-gerneth]

• Travis is currently missing the PHP 8 option ( https://travis-ci.community/t/php-8-0-missing/10132/17 ) but should be available next week
• This is mostly to see if/what needs to change to PHP8 support

Changes:

• Updated the README badges to link to the correct branch for this version
• Use ProphesizeTrait, prophesize integration has been moved into its own package phpspec/prophecy-phpunit
• Replaced calls to assertInternalType() with new assertions ( old ones have been removed )
• assertRegExp is deprecated and replaced
• Annotated a few tests with @medium that were running longer than 1 second and thus being stopped
• Update travis
• Fix at deprecation warnings in phpunit
• Update Doc-Header for 2021

[sandrokeil]

Maybe we should switch to GitHub actions.

[fritz-gerneth]

With PHP8 not working on Travis there is one apparent problem - other dependencies need to support PHP8 too. For the prooph/* components this probably is realistic. The biggest concern is about phpunit though - the minimum version to use would be phpunit@9 - requiring php > 7.3. That'd bump the version requirements of the prooph packages to 7.3 as well.

[sandrokeil]

I see no problem to increase the minimum PHP version if needed. Maybe rector can be used to make the code automatically compatible if needed. But indeed, some work is needed.

[fritz-gerneth]

Bump the minor version and make it a 7.5 version / branch then?

[sandrokeil]

We already have version 7.5, so it will be 7.6. What do you think @codeliner @prolic ? Should we also increase the PHP minimum version to 7.4? I see no reason to support PHP 7.3 anymore in this new version.

[sandrokeil]

Should we set PHP minimum version to ^7.4 for the new minor version?

[fritz-gerneth]

7.3 is still supported until end of next year. PHPUnit 9 supports 7.3 and 8 . Any specific reason to jump to 7.4 right away?

[sandrokeil]

Alright, we can stick to PHP 7.3, because we don‘t want to use new features.

[prolic]

good for me

[fritz-gerneth]

Inherently this is blocked by prooph/php-cs-fixer-config#8 / PHP-CS to support PHP8.

[enumag]

Note that php-cs-fixer (while it's not entirely ready to handle all PHP 8 features) no longer blocks installation under php 8. So in my opinion prooph/php-cs-fixer-config#8 can be merged now.

[sandrokeil]

I've updated prooph/php-cs-fixer-config#8 to support PHP ^7.1 || ^8.0 too.

[fritz-gerneth]

Awesome. I'll update the prooph packages then :)

[prolic]

see https://github.com/prooph/php-cs-fixer-config/releases/tag/v0.4.0

[coveralls]

Coverage decreased (-0.4%) to 99.07% when pulling 3ff1c61 on funct:7.x into 9b74792 on prooph:7.x.

[fritz-gerneth]

This should be good for review now :)

[prolic]

Looks awesome, just 2 minor notes.

[prolic]

still requires 7.1

[prolic]

I took care of this myself.

[prolic]

Thanks @fritz-gerneth, see here: https://github.com/prooph/event-store/releases/tag/v7.6.0