Added @cleanup to all pickle tests as requested

Author: dkua

lib/matplotlib/tests/test_pickle.py

@@ -126,6 +126,7 @@ def test_simple():
     pickle.dump(fig, BytesIO(), pickle.HIGHEST_PROTOCOL)
 
 
+@cleanup
 @image_comparison(baseline_images=['multi_pickle'],
                   extensions=['png'], remove_text=True)
 def test_complete():
@@ -194,6 +195,7 @@ def test_complete():
     assert_equal(fig.get_label(), 'Figure with a label?')
 
 
+@cleanup
 def test_no_pyplot():
     # tests pickle-ability of a figure not created with pyplot
     from matplotlib.backends.backend_pdf import FigureCanvasPdf as fc
@@ -206,12 +208,14 @@ def test_no_pyplot():
     pickle.dump(fig, BytesIO(), pickle.HIGHEST_PROTOCOL)
 
 
+@cleanup
 def test_renderer():
     from matplotlib.backends.backend_agg import RendererAgg
     renderer = RendererAgg(10, 20, 30)
     pickle.dump(renderer, BytesIO())
 
 
+@cleanup
 def test_image():
     # Prior to v1.4.0 the Image would cache data which was not picklable
     # once it had been drawn.
@@ -224,6 +228,7 @@ def test_image():
     pickle.dump(fig, BytesIO())
 
 
+@cleanup
 def test_grid():
     from matplotlib.backends.backend_agg import new_figure_manager
     manager = new_figure_manager(1000)