Should recordInterval live in CoreMetrics?

[ktoso]

I initially said in review that it should be in Metrics: #83

but maybe that was wrong; it does not depend on foundation but just dispatch hm.

swift-metrics/Sources/Metrics/Metrics.swift

Lines 42 to 44 in 44e8bfc

	func recordInterval(since: DispatchTime, end: DispatchTime = .now()) {
	self.recordNanoseconds(end.uptimeNanoseconds - since.uptimeNanoseconds)
	}

FYI @tomerd @slashmo

[tomerd]

I think depending on Dispatch in Core is fine, there are a couple of other ones in there that can move too