Convert the socket module to insist on bytes for input, and to return bytes
(not bytearray) on output.  Discovered a bunch of places that were still
depending on it accepting text strings.
diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index c01d998..97445a0 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -498,7 +498,7 @@
         sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         sock.settimeout(1)
         sock.close()
-        self.assertRaises(socket.error, sock.send, "spam")
+        self.assertRaises(socket.error, sock.send, b"spam")
 
     def testNewAttributes(self):
         # testing .family, .type and .protocol