MNT : remove deprecated delaunay code

Removed in PR matplotlib#2504

merged to master as 6afba8d

Author: tacaswell

ci/conda_recipe/run_test.py

@@ -1,11 +1,10 @@
 import os
-import platform 
+import platform
 import sys
 
 import matplotlib
 import matplotlib.pyplot
 import matplotlib._cntr
-import matplotlib._delaunay
 import matplotlib._image
 import matplotlib._path
 import matplotlib._png

doc/api/api_changes/code_removal.rst

@@ -0,0 +1,7 @@
+Code Removal
+````````````
+
+matplotlib.delaunay
+-------------------
+Remove the delaunay triangulation code which is now handled by Qhull
+via ``matplotlib.tri``

lib/matplotlib/__init__.py

@@ -1492,7 +1492,6 @@ def _jupyter_nbextension_paths():
     'matplotlib.tests.test_container',
     'matplotlib.tests.test_contour',
     'matplotlib.tests.test_dates',
-    'matplotlib.tests.test_delaunay',
     'matplotlib.tests.test_dviread',
     'matplotlib.tests.test_figure',
     'matplotlib.tests.test_font_manager',