vm: change display name: Lease object, Node object

fixes #6

circle/vm/models.py

@@ -75,6 +75,9 @@ class Node(TimeStampedModel):
         """
         pass  # TODO implement check
 
+    def __unicode__(self):
+        return self.name
+
 
 class NodeActivity(TimeStampedModel):
     activity_code = models.CharField(max_length=100)
@@ -119,6 +122,9 @@ class Lease(models.Model):
     def delete_interval(self, value):
         self.delete_interval_seconds = value.seconds
 
+    def __unicode__(self):
+        return self.name
+
 
 class InstanceTemplate(BaseResourceConfigModel, TimeStampedModel):