lithology doesn't yet exist on this branch, removing

Author: kbarnhart

test_notebooks.py

@@ -145,9 +145,9 @@ def test_set_BCs_on_voronoi():
     assert errors == []
 
 
-def test_lithology_and_litholayers():
-    nb, errors = _notebook_run(os.path.join(_TEST_DIR, "lithology/lithology_and_litholayers.ipynb"))
-    assert errors == []
+# def test_lithology_and_litholayers(): # this doesn't exist on this branch yet
+#     nb, errors = _notebook_run(os.path.join(_TEST_DIR, "lithology/lithology_and_litholayers.ipynb"))
+#     assert errors == []
 
 
 def test_reading_dem_into_landlab():