Bugfix issue#222

[iotanbo]

Bug description:
When writing symlinks to .zip or .tar archive, Write method uses the archive path instead of real path to access a symlink on the file system. This causes errors like readlink: readlink path/to/some/file: no such file or directory.

Bug fix:

1. Added SrcPath field to archiver.FileInfo so that Write method can use it to read the symlink.
2. Added github actions for Ubuntu, MacOS and Windows for in-place test automation (this may be undone if required).

[mholt]

Thanks for this. It's a likely approve, I'm mostly wondering if the GitHub actions should replace our broken Azure CI. And maybe the CI changes should be on a different PR?

[iotanbo]

Thanks for the reply. I reverted all changes related to CI.

[iotanbo]

Noticed that this pull request solves same issue as https://github.com/mholt/archiver/pull/201/files and https://github.com/mholt/archiver/pull/230/files, the difference is that this one does it for both .zip and .tar archives while the other only for .tar.
It looks like there are at least 3 PRs fixing the same issue, and the issue has been reported few times as well.

[mholt]

Thanks, will try to get this merged. Just one nit before doing so.

[mholt]

Suggested change

	SrcPath string
	SourcePath string

Generally I prefer to spell out words if it's not cumbersome, and I think we can in this case, since "source" is a pretty short word.

[iotanbo]

Done.

[mholt]

LGTM, thanks!

Did you still want to use your CI files? We could look at those in another PR.

[iotanbo]

OK, by the way the duplicate issue #202 and PRs #201 and #230 might also be closed.