Added a 'deleted' field to all models. Specifically to:
- plcorebase
- user (which does not derive from plcorebase)
diff --git a/planetstack/core/models/plcorebase.py b/planetstack/core/models/plcorebase.py
index f19776f..ccdeac7 100644
--- a/planetstack/core/models/plcorebase.py
+++ b/planetstack/core/models/plcorebase.py
@@ -28,6 +28,7 @@
     enacted = models.DateTimeField(null=True, default=None)
     backend_status = models.CharField(max_length=140,
                                       default="Provisioning in progress")
+    deleted = models.BooleanField(default=False)
 
     class Meta:
         abstract = True