Bump Nuspec Version

Bumping the version of the nuspec file requires a little tweaking and I got some help from the slack powershell community to ensure I handled the xml parsing correctly. This was the result. If you are running a chocolatey package build or equivalent nuspec build via an agent and want a way to ensure the latest build updates the build version incrementally this should help.

This snippet should help give you a way to bump a nuspec file version programmatically.

I modified the logic to support -WhatIf since I'm a fan of being able to run stuff like this without actually breaking things first.