A few years ago Elizabeth Holmes, boss of Theranos, dressed up as Queen Elizabeth 1 for the company’s Halloween party. At the time she reigned over Silicon Valley’s startup scene. In 2013-2015 she raised around $700m to fund her firm, which had supposedly developed a way to test blood with a single pinprick. MS Holmes was hailed as the next Steve Jobs and the youngest self-made billionaire in history. At its peak, Theranos claimed a…