This may just be the absolute best casting EVER. Mamie Gummer, Caitlin FitzGerald and Candice King have all boarded the adaptation of We Were Liars. The series, which is inspired by E. Lockhart’s novel of the same name, comes from Julie Plec, Carina Adly MacKenzie, Universal Television and Amazon MGM Studios. Julie Plec and Carina Adly MacKenzie reuniting…