Add W503 to default ignore list

Closes #498

Author: sigmavirus24

docs/intro.rst

@@ -392,7 +392,7 @@ This is the current list of error and warning codes:
 +------------+----------------------------------------------------------------------+
 | **W5**     | *Line break warning*                                                 |
 +------------+----------------------------------------------------------------------+
-| W503       | line break occurred before a binary operator                         |
+| W503 (*)   | line break occurred before a binary operator                         |
 +------------+----------------------------------------------------------------------+
 +------------+----------------------------------------------------------------------+
 | **W6**     | *Deprecation warning*                                                |

pep8.py

@@ -65,7 +65,7 @@
 __version__ = '1.8.0-dev'
 
 DEFAULT_EXCLUDE = '.svn,CVS,.bzr,.hg,.git,__pycache__,.tox'
-DEFAULT_IGNORE = 'E121,E123,E126,E226,E24,E704'
+DEFAULT_IGNORE = 'E121,E123,E126,E226,E24,E704,W503'
 try:
     if sys.platform == 'win32':
         USER_CONFIG = os.path.expanduser(r'~\.pep8')

testsuite/test_api.py

@@ -181,7 +181,7 @@ def parse_argv(argstring):
         self.assertEqual(options.select, ())
         self.assertEqual(
             options.ignore,
-            ('E121', 'E123', 'E126', 'E226', 'E24', 'E704')
+            ('E121', 'E123', 'E126', 'E226', 'E24', 'E704', 'W503')
         )
 
         options = parse_argv('--doctest').options