“Rosaline” is a comedic twist on Shakespeare’s “Romeo and Juliet” in which the classic love story is told from the perspective of Juliet’s cousin Rosaline (Kaitlyn Dever)–Romeo’s recent ex-girlfriend. Crushed when Romeo (Kyle Allen) dumps her after meeting Juliet (Isabela Merced), sharp but idealistic Rosaline schemes to foil the famous romance and win back her guy.