Lyttelton theatre, LondonA group of friends in 1930s New York pursue diverging dreams in a transfixing production of Pearl Cleage's play directed by Lynette Linton 'You're a genius with a dream, and I'm just a coloured girl out of a job," complains Angel to her gay best friend, Guy, with whom she shares an apartment in a big old house that is no match for a Harlem heatwave. Angel is a showgirl who has lost her liveli…