Rely on flakey's new ability to skip stdin errors

Resolves our half of tickets #53, and #53 I believe.

flake8/main.py

@@ -92,8 +92,8 @@ def check_file(path, ignore=(), complexity=-1):
 
 
 def check_code(code, ignore=(), complexity=-1):
-    warning = flakey.check(code, 'stdin')
+    warning = flakey.check(code, '<stdin>')
-    warnings = flakey.print_messages(warning, ignore=ignore)
+    warnings = flakey.print_messages(warning, ignore=ignore, code=code)
     warnings += pep8style.input_file(None, lines=code.split('\n'))
     if complexity > -1:
         warnings += mccabe.get_code_complexity(code, complexity)

flake8/util.py

@@ -1,6 +1,7 @@
 from __future__ import with_statement
 import re
 import os
+from io import StringIO
 
 pep8style = None
 
@@ -29,14 +30,18 @@ def skip_line(line):
 _NOQA = re.compile(r'flake8[:=]\s*noqa', re.I | re.M)
 
 
-def skip_file(path):
+def skip_file(path, source=None):
     """Returns True if this header is found in path
 
     # flake8: noqa
     """
-    if not os.path.isfile(path):
+    if os.path.isfile(path):
+        f = open(path)
+    elif source:
+        f = StringIO(source)
+    else:
         return False
-    f = open(path)
+
     try:
         content = f.read()
     finally: