Improve licensing of tests source code

[Silvanoc]

The source code files for the conformance tests don’t provide the typical Apache v2.0 licensing headers. The copyright holders are not explicitly listed either. It would make sense to have them for clearer licensing, simplifying contributions and reuse.

This PR adds the licensing headers provided by the Apache v2.0 license itself. It should also add the corresponding copyright holders.

This information should also help ensuring that the license information does not get lost, if someone comes to the idea of only copying the directory with the conformance tests.

Disclaimer: I am not a lawyer.

[jorydotcom]

Hi @Silvanoc thank you for your PR and the email to dev@!

There is some excellent guidance provided by an LF Legal team member and open source copyright expert that you might find useful: https://www.linuxfoundation.org/blog/blog/copyright-notices-in-open-source-software-projects

Would you be open to amending your PR to generalize the copyright notice?

[Silvanoc]

There is some excellent guidance provided by an LF Legal team member and open source copyright expert that you might find useful: https://www.linuxfoundation.org/blog/blog/copyright-notices-in-open-source-software-projects

@jorydotcom thanks, I wasn't aware of it.

Would you be open to amending your PR to generalize the copyright notice?

Of course! That is exactly the intention! Though I would prefer to stick to providing the template in my commit and a project maintainer adds a commit with the desired copyright notice. Then I'd mark the PR as ready for review.

Ideally a list of contributors is also kept in which organizations can be entered. I've added a 2nd commit with that proposal? Reason for that? Because with the German working regulation that applies to my contributions, I am author, and my company is copyright holder.

[Silvanoc]

@jorydotcom I've adapted the patch to the LF guidelines.

[mikebrow]

LGTM

[sudo-bmitch]

Looking through the overall OCI organization, I'm seeing a variety of copyrights. Many are to the Linux Foundation. Some are to OCI Contributors. At least one is still licensed to the contributing company. Within distribution-spec, we are now inconsistent between the directories with "contributors to the Open Containers Distribution Specification" being added here.

I'm also unclear on whether we only need the copyright notice in Go code, or if files like the spec markdown files and yaml files defining github actions also need copyright notices. And many of the notices include a single year value, presumably the year the file was first added to the project. Occasionally the year is provided as a range.

It would be good for LF Legal to clarify if a single value should be used across the projects (at least for when code does not come from an external location), and what that value should be, both in file headers and the LICENSE file. @jorydotcom would you follow up on this?

[mikebrow]

fair.. I suggest "adding" open containers distribution specification at the top of the files and not "removing" any of the existing copyrights that would be just below.