Doesn't work on iOS

[0x6080]

Love this for logging, but some of my teamates had complaints that the OS specific stuff is not compatible with iOS.

It would probably be fine if there was just no-op behavior for, ie:

	log.Logger = log.Output(horizontal.ConsoleWriter{Out: os.Stderr})
	zerolog.NewConsoleWriter()

just ended up doing "normal" zerolog output.

But with the current setup, it won't even compile. Would be great to get that to work!