At the appointed time I make my way through Trafalgar Square and down Whitehall, past the Admiralty, the old War Office and the Department of Defence, to a palatial and very official-looking building called Whitehall Court. I push on a heavy wooden door. I’m in Huckletree Public Hall in Westminster, London. It’s a co-working office catering specifically for something called gov-tech, which means “businesses looking to disrupt and transform the public sector.” Public Hall is emphatically not decorated in the public sector style. It’s bright and modish. There are copper taps, neon signs and a blue velvet banquette.  I’m here…