Update payoff plot test for matplotlib 3+

Author: marcharper

axelrod/tests/unit/test_plot.py

@@ -192,23 +192,13 @@ def test_payoff_with_title(self):
         self.assertIsInstance(fig, matplotlib.pyplot.Figure)
         plt.close(fig)
 
-    @unittest.skipIf(matplotlib.__version__.startswith('3'),
-                     "Colorbar position differs in matplotlib versions")
     def test_payoff_with_passed_axes(self):
         plot = axelrod.Plot(self.test_result_set)
         fig, axarr = plt.subplots(2, 2)
         self.assertEqual(axarr[0, 1].get_xlim(), (0, 1))
 
         plot.payoff(ax=axarr[0, 1])
         self.assertNotEqual(axarr[0, 1].get_xlim(), (0, 1))
-        # Ensure color bar draw at same location as boxplot
-        color_bar_bbox = fig.axes[-1].get_position().get_points()
-        payoff_bbox_coord = fig.axes[1].get_position().get_points()
-        self.assertEqual(
-            color_bar_bbox[1, 1],
-            payoff_bbox_coord[1, 1],
-            msg="Color bar is not in correct location.",
-        )
 
         # Plot on another axes with a title
         plot.payoff(title="dummy title", ax=axarr[1, 0])