For decades, sci-fi has told us voice operation is the way forward. Now AI butlers are here – and you don’t have to be Mark Zuckerberg do build your ownThe Internet of Things is here, they cried. Great, but do I really have to pull out my smartphone to do everything? Pushing a button was so much easier. Can’t I just talk to my house now? Can I scream “red alert” and have my lights flash red? The Star Trek dream