“People We Meet on Vacation,” by Emily Henry (Berkley)A truly good romantic comedy, whether it be a novel or a movie, justifies why two people are drawn to each other. It builds a case for the relationship so it makes sense why they’re together.In Emily Henry’s latest book, “People We Meet on Vacation,” she does just that, introducing Poppy and Alex, two polar opposites who met in college but happened to both be from the same town in Ohio.