Joe Otterson TV ReporterDakota Fanning has joined the cast of the Showtime drama series “Ripley,” Variety has learned.The series is based on Patricia Highsmith’s Tom Ripley novels. She joins previously announced cast members Andrew Scott and Johnny Flynn.In the series, Tom Ripley (Scott), a grifter scraping by in early 1960s New York, is hired by a wealthy businessman to travel to Italy to try to convince his vagabond son to return home.