full support to PHP 8.0 + add support for CurlHandle resource objects

[ildyria]

Q	A
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Related tickets	fixes #68, closes #70
Documentation	-
License	MIT

What's in this PR?

• In PHP 8.0, Curl resources are changed to CurlHandle class objects. This changes DocBlock parameters and other areas where provided handles are checked with is_resource(), which now needs to account for the replaced CurlHandle class objects.

• In order to apply the test, it uses the github workflows.

• Migrate from php-http/client-integration-tests from ^2.0 to ^3.0

Why?

• The author of #70 has not reacted since his PR, so nothing is moving.

• Because in PHP 8.0, Curl handles are no longer resources, and this libraries is_resource no longer return true for valid Curl handlers.

• Migrate from php-http/client-integration-tests so that PHP 8.0 is supported.

Example Usage

is_resource(curl_init()); // true in PHP < 8.0
is_resource(curl_init()); // false in PHP >= 8.0

[ildyria]

@dbu I incorporated your suggestions to #70 in this PR.

[ildyria]

Full CI run here: https://github.com/ildyria/curl-client/actions/runs/413449950

[ildyria]

@dbu fixed as per requested.

CI Run here: https://github.com/ildyria/curl-client/actions/runs/416459080 I enabled coverage as per the travis file, but I expect it to crash as I don't have access to the secrets in the repo.

[dbu]

thanks a lot, this is coming good!

as you expected, the coverage fails in your repository. i will merge and see if it works from our repository.

[dbu]

thanks for the review graham - i was so excited for php 8 that i missed those details. i do a cleanup in #74

[Ayesh]

Author of #70 - thank you for picking up it in here, I'm happy to see it merged now. I apologize about my delays in the other PR, I was having some issues lately. 🙏🏼

[dbu]

thanks for having gotten the ball rolling @Ayesh and @ildyria for wrapping it up. collaboration for the win!