Fix visualization error for PropertyLayers on HexGrids (#2868).

Author: flucco

mesa/visualization/backends/matplotlib_backend.py

@@ -391,7 +391,7 @@ def draw_propertylayer(self, space, property_layers, propertylayer_portrayal):
             elif isinstance(space, HexGrid):
                 hexagons = self.space_drawer.hexagons
                 norm = Normalize(vmin=vmin, vmax=vmax)
-                colors = data.ravel()
+                colors = data.T.ravel()
 
                 if color:
                     normalized_colors = np.clip(norm(colors), 0, 1)