#9 - enables cache clearing via HTTP PURGE method when FASTLY_API_KEY is not provided
This release enables new behavior when the FASTLY_API_KEY is not provided to the cache-clear Kiln plugin. Rather than make an authenticated request against the Fastly API domain, this will make a PURGE request directly against the provided URL(s).
Running cache-clear in this mode is a trade-off.
It will protect API keys from being passed to the client (and ease any uncertainties about the scope of those keys), but it requires some layer of network-level privilege (eg. a Fastly IP whitelist for the PURGE method).