planetstack/core/models/role.py

role field can be null or blank
diff --git a/planetstack/core/models/role.py b/planetstack/core/models/role.py
index 6b0e7a6..bd97f52 100644
--- a/planetstack/core/models/role.py
+++ b/planetstack/core/models/role.py
@@ -8,7 +8,7 @@
 class Role(PlCoreBase):
 
     role_type = models.CharField(max_length=80, verbose_name="Name")
-    role = models.CharField(max_length=80, verbose_name="Keystone role id")
+    role = models.CharField(max_length=80, verbose_name="Keystone role id", null=True, blank=True)
     description = models.CharField(max_length=120, verbose_name="Description")
     content_type = models.ForeignKey(ContentType, verbose_name="Role Scope")