Allow cache to be re-generated on-demand without first deleting it

[traviskroberts]

I'm not sure if this addition would be useful to anyone else, but it's something that my current employer could definitely use.

We have an endpoint that is very expensive to generate when there is no cache. When we clear the cache, if the app is under heavy load, we get stressed db and app servers.

I'm open to any feedback about changes/additions you'd like to see with this feature.