Django Revision?

gistfile1.py

#import reversion

from django.db import models
from django.contrib.auth.models import User

class RevisionManager(models.Manager):
    def get_queryset(self):
        return super(RevisionManager, self).get_queryset().latest()

class Ticket_Status(models.Model):
	user = models.ForeignKey(User,null=True,blank=True)
	STATUS_CHOICES = (
		('OPEN', 'Open'),
		('SOLVED', 'Solved'),
		('CLOSED', 'Closed'),
		('WAITING_FOR_VENDOR', 'Waiting For Vendor'),
	)
	status = models.CharField(max_length=25,
							  choices=STATUS_CHOICES,
							  default='OPEN')
	date_added = models.DateTimeField('date_added',auto_now_add=True, editable=False)

	objects = RevisionManager()

	def __unicode__(self):
		return u'%s' % (self.name)
	class Meta:
		verbose_name_plural = "statuses"
		ordering = ['date_added']

class Ticket(models.Model):
	tech = models.ForeignKey(User,null=True,blank=True)
	techs_watching = models.ManyToManyField(User,related_name='techs_watching',null=True,blank=True)
	user = models.ForeignKey(User)
	problem = models.TextField(null=True,blank=True)
	#...
	status = models.ManyToManyField(Ticket_Status,related_name='status',null=True,blank=True)
	#...
	date_added = models.DateTimeField('date_added',auto_now_add=True, editable=False)
	date_updated = models.DateTimeField('date_updated',auto_now_add=True, auto_now=True, editable=False)