TST: Increase tolerances for Ghostscript 10.06

- `test_bbox_inches_tight_raster` differs by a single pixel in the
  middle of the line
- `test_interp_nearest_vs_none` shifts the middle of the image over one
  pixel, causing a line of differences

Author: QuLogic

lib/matplotlib/tests/test_bbox_tight.py

@@ -110,7 +110,7 @@ def test_bbox_inches_tight_clipping():
     plt.gcf().artists.append(patch)
 
 
-@image_comparison(['bbox_inches_tight_raster'],
+@image_comparison(['bbox_inches_tight_raster'], tol=0.15,  # For Ghostscript 10.06+.
                   remove_text=True, savefig_kwarg={'bbox_inches': 'tight'})
 def test_bbox_inches_tight_raster():
     """Test rasterization with tight_layout"""

lib/matplotlib/tests/test_image.py

@@ -36,7 +36,7 @@ def test_alpha_interp():
     axr.imshow(img, interpolation="bilinear")
 
 
-@image_comparison(['interp_nearest_vs_none'],
+@image_comparison(['interp_nearest_vs_none'], tol=3.7,  # For Ghostscript 10.06+.
                   extensions=['pdf', 'svg'], remove_text=True)
 def test_interp_nearest_vs_none():
     """Test the effect of "nearest" and "none" interpolation"""