Fixed a missed raw_input call on Python 3

Author: dcwatson

haystack/management/commands/clear_index.py

@@ -2,6 +2,7 @@
 from __future__ import unicode_literals
 from optparse import make_option
 import sys
+import six
 
 from django.core.management.base import BaseCommand
 
@@ -34,7 +35,7 @@ def handle(self, **options):
             print("WARNING: This will irreparably remove EVERYTHING from your search index in connection '%s'." % "', '".join(using))
             print("Your choices after this are to restore from backups or rebuild via the `rebuild_index` command.")
 
-            yes_or_no = raw_input("Are you sure you wish to continue? [y/N] ")
+            yes_or_no = six.moves.input("Are you sure you wish to continue? [y/N] ")
             print
 
             if not yes_or_no.lower().startswith('y'):