Update Humanizer reference to Humanizer.Core

[seangwright]

Humanizer updated their repository and released version 2.0 which restructured their project. Humanizer.Core now suffices as a library for your project and doesn't include all of the localization .dlls.

I can make a pull request to update this project to reference the updated Humanizr nuget package if you would be willing to update your Nuget package.

Thanks!

Edit --

Here is my pull request #2

[gavynriebau]

Pull request has now been merged