Adds a new function Stop-VSTeamBuild

[brittandeyoung]

PR Summary

• Adds a new function Stop-VSTeamBuild which allows cancelling a build using the build id. Closes #206

PR Checklist

• [X] Write Help
• [X] Write Unit Test
• [X] Update CHANGELOG.md

[SebastianSchuetze]

Hi @brittandeyoung looks great already. One small thing is missing. Could you create a help document like the following?https://github.com/DarqueWarrior/vsteam/blob/master/.docs/Add-VSTeamBuild.md

A cmdlet should have help page which links the synopsis. Thank you!

[brittandeyoung]

Hi @brittandeyoung looks great already. One small thing is missing. Could you create a help document like the following?https://github.com/DarqueWarrior/vsteam/blob/master/.docs/Add-VSTeamBuild.md

A cmdlet should have help page which links the synopsis. Thank you!

I have added the requested help page. Please let me know if there is anything else I am missing.

[SebastianSchuetze]

I merged the PR and adjusted a few lines of code for optimization and added a unit test for testing the pipeline feature for build IDs.

Thanks for the good and quick contribution!