Merge pull request matplotlib#3221 from katyhuff/mac_pep

Fixes matplotlib#3219 by ignoring pep8 noncomplicant auto-generated file.

Author: NelleV

Diff for: lib/matplotlib/tests/test_coding_standards.py

@@ -35,7 +35,8 @@
                  '_gtkagg.py',
                  '_backend_gdk.py',
                  'pyparsing*',
-                 '_qhull.py']
+                 '_qhull.py',
+                 '_macosx.py']
 
 PEP8_ADDITIONAL_IGNORE = ['E111',
                           'E112',