wrhs cli should do an npm version check against latest and offer an upgrade

[msluther]

Since wrhs is something that people will likely have installed globally, it should check it's version against latest and inform people that a newer version is available. That way people could more easily know when new versions come out.

The update prompt should probably let them know the new version number that's available and link to this repos changelog/release so they can easily see what has changed.