Add the Seven Sisters colleges to the growing chorus of critics of Steve Bannon, the “alt-right” leader and Breitbart chairman who was appointed as chief strategist to President-elect Donald Trump last week. In an open letter Monday, the heads of the seven northeastern liberal arts schools called on Bannon to “take a more expansive, informed and tolerant world view” in his new position. They specifically cited a 2011 interview in which Bannon used a derogatory lesbian slur in reference to Seven Sisters college alumnae and the women’s liberation movement.