Error when no data for stories

[todo]

Also see #11 #12 #13

claw/claw/Stories/Newest/NewestFetcher.swift

Lines 86 to 91 in f4931d8

	completion?(nil) // todo: actually do error
	}
	} catch {
	print ("Error \(error)")
	completion?(error)
	}

Should show an error if there is an actual error.

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This issue was generated by todo based on a todo comment in f4931d8. It's been assigned to @twodayslate because they committed the code.