Improve gilded-wordpress to tolerate newer server if semver compatible

[Krinkle]

Right now, the moment gilded-wordpress is updated on the server-side, clients in content repos like api.jquery.com are broken unless all 12 repos are updated at the same time.

Note that in practice, nothing breaks because:

1. We ignore the lock file (Remove npm update step from builder notifier scripts #38).
2. These aren't long-running services, so nothing actually "breaks". It just means you have to, at some point, update package.json in a given content repo before you can deploy changes in content from that same repo. The content repos are quite stable, so it's perfectly fine for them to be out of sync for a few weeks until someone actually wants to deploy from them and push a tag. Until then, there's no issue either way.