Fix a few places that broke due to a recent change to io.py.

Lib/test/test_urllib2.py

@@ -673,7 +673,7 @@ class HandlerTests(unittest.TestCase):
                 self.assertEqual(req.type, "ftp")
 
     def test_http(self):
-        class MockHTTPResponse:
+        class MockHTTPResponse(io.IOBase):
             def __init__(self, fp, msg, status, reason):
                 self.fp = fp
                 self.msg = msg

Lib/urllib2.py

@@ -1079,6 +1079,8 @@ class AbstractHTTPHandler(BaseHandler):
         # Add some fake methods to the reader to satisfy BufferedReader.
         r.readable = lambda: True
         r.writable = r.seekable = lambda: False
+        r._checkReadable = lambda: True
+        r._checkWritable = lambda: False
         fp = io.BufferedReader(r)
 
         resp = addinfourl(fp, r.msg, req.get_full_url())