Added Wiki cmdlets

[gm0d]

PR Summary

Added:

• Add-VSTeamWiki
• Get-VSTeamWiki
• Remove-VSTeamWiki

to interact with provisioned and code wiki

PR Checklist

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

[SebastianSchuetze]

@gm0d thanks for the PR. I can't commit anything to your PR. Either you fix the mistake yourself or you give me permission to commit to your PR.

You have a sample called refenced 'SampleFiles/Get-VSTeamWiki.json' but in your repo it is named 'Get-VsTeamWiki.json'. Mac and Linux are case sensitive. Please renamed the file to get the build run successfully.

[SebastianSchuetze]

Very nice PR! It is good to see when good structured code and tests are written like the rest of the code in the module.

Just two minor changes would be nice before we can merge it.

[SebastianSchuetze]

@gm0d Looks good. Just one thing. Could you pull the latest changes from our trunk. There was a Script Analyzer problem that I fixed. When the build is successfully running through, then I can merge it.

[SebastianSchuetze]

Never mind. Build was successful. So I am merging.