FIX: Flush events after closing figures in macosx backend

Author: greglucas

lib/matplotlib/backends/backend_macosx.py

@@ -152,6 +152,7 @@ def __init__(self, canvas, num):
 
     def close(self):
         Gcf.destroy(self)
+        self.canvas.flush_events()
 
 
 @_Backend.export