Use Github API to alert on new releases for un-supported auto-update

[djw8605]

We only support auto-update for Mac. For the other platforms, we should notify them if there is a new release of HCCGo.

I envision this being part of the update notifier service. Also, this would probably use the node-github package.

1. Call the getLatestRelease function.
2. Parse the version with the node-semver package to tell if the latest release is newer than the current release.
3. If there is a newer release, show the link to the release page.

Don't have to do anything fancy like auto-download or anything. Just a link to the release page.