Added cmdlet Test-VSTeamYamlPipelines for testing YAML pipeline code

[SebastianSchuetze]

PR Summary

added a new cmdlet for a new API that was released the last sprint.

https://docs.microsoft.com/en-us/azure/devops/release-notes/2020/sprint-165-update#azure-pipelines-1

I still need to add some documentation first and change the changelog.

PR Checklist

• Write Help
• Write Unit Test
• Update CHANGELOG.md

[tomkerkhove]

Do we need 'VSTeam' prefix? For consistency reasons?

[SebastianSchuetze]

Do we need 'VSTeam' prefix? For consistency reasons?

@tomkerkhove, The whole module is called VSTeam and every cmdlet has it as well. Which is consistent with the e.g. AzureAD, Az, AzureRM modules. This is how you prevent also conflicts with other modules which could be loaded as well.
You can see it like a namespace.

[SebastianSchuetze]

@JustinGrote do you see any useful parameters that might make sense to add?

[tomkerkhove]

Sounds good to me!