zerver/management: Remove `import six`.

zerver/management/commands/email_mirror.py

@@ -25,7 +25,6 @@ recipient address and retrieve, forward, and archive the message.
 
 from __future__ import print_function
 
-import six
 from typing import Any, List, Generator
 
 import logging
@@ -65,10 +64,7 @@ def get_imap_messages():
             for msgid in num_ids_data[0].split():
                 status, msg_data = mbox.fetch(msgid, '(RFC822)')
                 msg_as_bytes = msg_data[0][1]
-                if six.PY2:
-                    message = email.message_from_string(msg_as_bytes)
-                else:
-                    message = email.message_from_bytes(msg_as_bytes)
+                message = email.message_from_bytes(msg_as_bytes)
                 yield message
                 mbox.store(msgid, '+FLAGS', '\\Deleted')
             mbox.expunge()

zerver/management/commands/realm_emoji.py

@@ -8,7 +8,6 @@ from django.core.management.base import BaseCommand, CommandParser
 from zerver.lib.actions import check_add_realm_emoji, do_remove_realm_emoji
 from zerver.lib.management import ZulipBaseCommand
 import sys
-import six
 
 class Command(ZulipBaseCommand):
     help = """Manage emoji for the specified realm
@@ -44,7 +43,7 @@ Example: ./manage.py realm_emoji --realm=zulip.com --op=show
         realm = self.get_realm(options)
         assert realm is not None  # Should be ensured by parser
         if options["op"] == "show":
-            for name, url in six.iteritems(realm.get_emoji()):
+            for name, url in realm.get_emoji().items():
                 print(name, url)
             sys.exit(0)