Make it possible to go from deployments to sites in the data model.
diff --git a/planetstack/core/models/site.py b/planetstack/core/models/site.py
index eea62fe..fe7fb93 100644
--- a/planetstack/core/models/site.py
+++ b/planetstack/core/models/site.py
@@ -21,7 +21,7 @@
     abbreviated_name = models.CharField(max_length=80)
 
     #deployments = models.ManyToManyField('Deployment', blank=True, related_name='sites')
-    deployments = models.ManyToManyField('Deployment', through='SiteDeployments', blank=True, help_text="Select which sites are allowed to host nodes in this deployment")
+    deployments = models.ManyToManyField('Deployment', through='SiteDeployments', blank=True, help_text="Select which sites are allowed to host nodes in this deployment", related_name='sites')
     tags = generic.GenericRelation(Tag)
 
     def __unicode__(self):  return u'%s' % (self.name)