Revert #954 and update redis-py to at least 3.2.0 (#1011)

This reverts #954, and bumps the required redis-py dependency to 3.2.0
to include this fix:

4e1e748092

Fixes #1006

kombu/transport/redis.py

@@ -931,22 +931,8 @@ class Channel(virtual.Channel):
         if asynchronous:
             class Connection(connection_cls):
                 def disconnect(self):
-                    # NOTE: see celery issue #3898
-                    # redis-py Connection shutdown()s the socket
-                    # which causes all copies of file descriptor
-                    # to become unusable, however close() only
-                    # affect process-local copies of fds.
-                    # So we just override Connection's disconnect method.
-                    self._parser.on_disconnect()
+                    super(Connection, self).disconnect()
                     channel._on_connection_disconnect(self)
-                    if self._sock is None:
-                        return
-                    try:
-                        # self._sock.shutdown(socket.SHUT_RDWR)
-                        self._sock.close()
-                    except socket.error:
-                        pass
-                    self._sock = None
             connection_cls = Connection
 
         connparams['connection_class'] = connection_cls
@@ -964,9 +950,9 @@ class Channel(virtual.Channel):
         return redis.ConnectionPool(**params)
 
     def _get_client(self):
-        if redis.VERSION < (2, 10, 5):
+        if redis.VERSION < (3, 2, 0):
             raise VersionMismatch(
-                'Redis transport requires redis-py versions 2.10.5 or later. '
+                'Redis transport requires redis-py versions 3.2.0 or later. '
                 'You have {0.__version__}'.format(redis))
         return redis.StrictRedis
 

requirements/extras/redis.txt

@@ -1 +1 @@
-redis>=2.10.5
+redis>=3.2.0