Focusing on racism and sexism in American theater, “Trouble in Mind” by the late Alice Childress is playing through Dec. 18 at Timeline Theatre, 615 W. Wellington Ave.Although it debuted off-Broadway in 1955, it is as significant and relevant today as it was then. It’s true that great progress has been made in recent years concerning diversity in writing, casting, direction as well as other roles in theatrical productions, but racism and sexism remain great matters of concern in society.Childress’ play addressed these …