Set up Azure Pipeline

[MarkLodato]

Set up an Azure Pipeline to run this demo. This will allow us to test it and verify that it works.

• [x] Created a slsa-framework organization in Azure DevOps.
• [x] Create an azure-devops-demo project.
• [X] Configure a pipeline to run the demo.
• [x] Configure GitHub to automatically run the pipeline on commit.
• [X] Add other members to the organization. (@TomHennen and @joshuagl for now - we're limited to 5)

[MarkLodato]

It worked: https://dev.azure.com/slsa-framework/azure-devops-demo/_build/results?buildId=3&view=artifacts&pathAsName=false&type=publishedArtifacts

I'll continue to refine it.