Contributing guide does not explain how to run existing tests

[Kyle J Strand]

Description

It is unclear how to run the existing xgen test suite, and it appears that doing so may require special permissions.

Details:

CONTRIBUTING.md recommends running the existing test suite, but does not give instructions for doing so. Running go test ./... in the root of the xgen repo results in the following error (repeated several times):

                Error:          Received unexpected error:
                                stat data/xsd: no such file or directory

Examining the GitHub Action workflow file, it appears that most of the tests live in a separate repository:

    - name: Checkout test XSD
      uses: actions/checkout@v2
      with:
        repository: xuri/xsd
        token: ${{ secrets.GIT_TOKEN }}
        path: data

...however, it appears the github.com/xuri/xsd repo is private (I get a 404 from that URL).

PS:

I have elided most of the sections from the template because they don't seem relevant, since I am not reporting a bug in xgen behavior per se. I am happy to provide additional info if asked!

For context, I was hoping to investigate #7 because it is blocking my work.

[xuri]

Thanks for your feedback. I have make the test collection repo as public, and I will investigate this issue later.