Update CI and fix build

[zmughal]

• Add initial GitHub Actions CI workflow
• Use Test::Alien for t/01_use.t
• Skip t/03_pcre2grep.t for system install
• Update URL for releases to GitHub. Fixes PCRE2 is now hosted on GitHub #10.
• Rewrite postamble
• Do not check bin_dir() if system install. No longer need Fix t/02_pcre2_config.t plan for system installation #7, Fixed test #2. #9.

[zmughal]

See build at https://github.com/zmughal/alien-pcre2/actions/runs/1834903558.

[wbraswell]

@zmughal
Why are we showing "All checks have failed, 1 failing check, AppVeyor build failed" ?

[zmughal]

@wbraswell, seems like AppVeyor did not install Strawberry Perl. I would recommend using Chocolatey: https://dev.to/yukikimoto/install-strawberry-perl-using-chocolatey-on-windows-4if3

I used to use AppVeyor myself and this was how I would set it up: https://github.com/zmughal-CPAN/p5-Alien-ZMQ-latest/blob/ff789fc7e317914e5f89b65d3c2bc95ca361e094/appveyor.yml

[zmughal]

As discussed, fixed the AppVeyor build (now tests with 32- and 64-bit Strawberry Perl).

[wbraswell]

@zmughal
It looks good so far!
For the record, can you please elaborate on the purpose for the "Rewrite postamble" commit?

[zmughal]

I wanted to simplify the build by removing what wasn't necessary. The build still passes.

[zmughal]

@wbraswell, this can now be released, correct?

[wbraswell]

@zmughal
You are wanting to release to CPAN, I assume?

[zmughal]

@wbraswell, yes, please! Released to CPAN. :-)