More companies are departing the Grocery Manufacturers Association. Politico reports that the Kraft Heinz Company and DowDuPont are the latest to part ways with the association. The two companies join the Campbell Soup Company, Nestle, Dean Foods, Mars, Tyson Foods and Unilever. Politico says GMA staff are also leaving, including high-ranking executives. GMA pledges changes: A spokesperson for GMA said …