Applications are surging for New York University’s School of Medicine after the university announced last year that its medical program would be tuition-free for all students. But NYU isn’t the only school trying to offer free medical training. Dozens of colleges and universities are taking courses in healthcare and medicine online—and making them free or low-cost—with massive online course platforms. Coursera, a company that hosts massive online courses and degrees, is the latest entrant among a growing number of online…